The Fundamental Principles of Seating and Positioning in Children and Young
People with Physical Disabilities
Laura Neville BSc (Hons) Occupational Therapy Student
University of Ulster
Supervised by:
Mrs Jackie Quigg (School of Health Sciences UU)
Dr Alison Porter Armstrong (Health and Rehabilitation Sciences Research Institute UU)
Commissioned by James Leckey Design Limited
Summer 2005
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Project Background James Leckey Design Limited (Northern Ireland) is a company specialising in equipment design, manufacture and provision for children with physical disabilities. As part of a 2 ½ year project, involving the University of Ulster (with Mrs Jackie Quigg and Dr Alison Porter Armstrong) to research the clinical effectiveness of one of their product ranges, the company commissioned three BSc (Hons) Occupational Therapy students (Laura Neville, Linda McNamara and Glenda Alexander) to conduct critical reviews of the literature in three designated areas: 1) Fundamental Principles of Seating and Positioning in Children and Young People with Physical Disabilities. (Laura Neville) 2) Postural Management: Components of Specialised Seating Equipment. (Linda McNamara) 3) Early Intervention and the Effects of Adaptive Seating on Function. (Glenda Alexander) The critical reviews undertaken were completed between June and August 2005 and conducted as part of a steering group comprising of: Mr James Leckey (James Leckey Design Limited); Mr Noel McQuaid (Technical Director, James Leckey Design Limited), Mrs Clare Wright (Research Occupational Therapist, James Leckey Design Limited), Mrs Jackie Quigg (UU) and Dr Alison Porter Armstrong (UU), with formal supervision provided on a weekly basis. This is the first of three critical reviews commissioned by James Leckey Design reviewing and critically appraising the literature regarding the fundamental principles of seating and positioning in children and young people with physical disabilities. Acknowledgements
I would like to thank Mrs Jackie Quigg and Dr Alison Porter Armstrong for their continued support, direction and guidance in regarding completion of this review. Thanks also to James, Noel and Clare for providing the opportunity to engage in this project and thank you to Linda and Glenda for your constant support and encouragement and making the completion of this review possible.
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Index of Contents Page Introduction 3 Methods 4 The relationship between posture, movement, stability and function 4 Normal posture 6 The action of sitting 6 Neutral sitting posture 7 The 90-90-90 position – how functional? 8 Functional Sitting Position 9 Factors affecting positioning 13 Primitive reflex activity 13 Structural asymmetries 15 Abnormal muscle tone 18 Childhood conditions 20 Cerebral Palsy 20 Congenital hip deformity/Developmental Dysplasia 23 Rett Syndrome 24 Duchenne Muscular Dystrophy 25 Spina Bifida 26 Conclusion 27 References 28 Appendices 35
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Principles of Seating and Positioning
Introduction
The prescription of appropriate seating equipment for children and young people with physical disabilities is important, in order to provide an optimal seated position from which they may engage in functional activities. Research has evidenced the benefits of adaptive seating to include improved postural alignment (Miedaner 1990; Myhr and von Wendt 1991), development of motor skills (Green and Nelham 1991), helping the prevention of fixed deformity (Pountney et al 2002) and facilitation of upper extremity function (Myhr and von Wendt 1991; Myhr et al 1995, van der Heide 2003). It is imperative that health professionals prescribing and engineers designing seating equipment are well informed regarding the fundamental seating principles that dictate the sitting postures of children and young people and the impact they have on long term health and function.
Traditional emphasis regarding positioning is placed on achieving an upright
symmetrical posture utilising the 90-90-90 flexion at the hips, knees and ankles position (Green and Nelham 1991; Ham et al 1998; Erhardt and Merril 1998, Hong 2002). Although an important posture to achieve, this upright position is suggested as non-functional (Engström 2002) and difficult to maintain over time (Howe and Oldham 2001), resulting in adoption of compensatory postures which may lead to long term deformity and further deterioration when appropriate external support is unavailable. Seating solutions may require reaching a balance between an upright anatomical symmetrical posture and ability to function (Ham et al 1998; Pope 2002).
The focus of this research was to review and critically appraise the literature
regarding the fundamental principles of seating and positioning used with children and young people with physical disabilities. The report uses evidence from published studies, and expert opinion to identify seating and positioning principles used with children and young people with disabilities, the benefits of optimal positioning and problems which may incur as a result of incorrect positioning. An overview of normal and abnormal postures is discussed from biomechanical and neurophysiological viewpoints. Common childhood neuromotor and neuromuscular conditions are considered with respect to clinical manifestations and resultant positioning problems which health professionals and engineers must consider when prescribing / designing seating interventions to promote long term health and functional independence.
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Methods
A literature search was conducted using the following electronic data bases; AMED (Allied and Complimentary Medicine), ASSIA (Applied Social Sciences Index and Abstracts), BIDS, British Nursing Index, CINHAL (Cumulative Index of Nursing and Allied Health Literature), Embase, ISI Web of Science, MEDLINE, OTDbase, Pubmed, Proquest, Psychinfo and Zetoc. Criteria for considering relevant literature for review required all articles to be in the English language, and published between January 1990 up to and including May 2005. On occasions, earlier dated key papers were included for relevance. Tables 1-7 (appendix 1) identify the key words utilised in the search strategy with respect to the data bases searched. Electronic database searching was supplemented with hand searches, citation searches of reference lists, conference proceedings and retrieving relevant literature from published textbooks. The McMaster critical review forms (Law et al 2002) were used as a guideline for critiquing relevant studies attained.
The relationship between posture, movement, stability and function
Posture may be defined as, “ the position of one or many body segments in relation to one another and their orientation in space” (Ham et al, p26). Body ‘segments’ are referred to as the head, thorax, pelvis, lower limbs and feet, whilst the body ‘linkages’ are considered as the spinal joints, hips, knees, ankle and shoulder joints (Pope 2002). When considering posture, one should not consider it as static, but as an active and dynamic process which underpins movement and function (Hong 2005). Normally, our postures continuously shift and change position to facilitate movement to engage in functional activities. Pope (2002) identifies that posture is a prerequisite for movement. Howe and Oldham (2001) also highlight that posture and movement are inextricably linked, referring to posture as a temporary arrested movement, which is in a constant state of change. From a neurodevelopmental perspective Nichols (2001) suggests that the development of postural control and acquisition of motor milestones are intrinsically linked. Ham et al (1998) support this assumption highlighting that there is constant neuromotor activity being used to maintain body balance and posture. Engström (2002) further suggests that biological and physiological influences affect body position and posture. This is also in addition to the somatosensory, vestibular and musculoskeletal systems (Nichols 2001).
For functional movement to occur in sitting, literature suggests that stability of proximal body parts (pelvis, spine and shoulders) is a prerequisite for distal control (Green and Nelham 1991; Herman and Lange 1999). For example, pelvic stability is required for the spine so that the neck is free to move; shoulder girdle stability is required to stabilise the arm for fine motor and hand control. Washington et al (2002) however suggests that there is limited published research to support this hypothesis
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suggesting that the relationship between proximal stability and distal control is not necessarily one of cause and effect. This is supported by Case-Smith et al (1989) who identified weak correlations between proximal control and hand function in typically developing children as assessed by the Posture and Fine Motor Assessment of Infants (Case-Smith 1987). However evidence suggests that clinicians and therapeutic seating do utilise the principle of achieving pelvic stabilisation to maximise distal control for function in children with neuromotor dysfunction. This is illustrated in the literature by the use of anterior pelvic stabilization devices in seating interventions (Reid and Rigby 1996; Reid 1996, Rigby et al 2001) and by promoting anterior pelvic tilt via the use of the functional sitting position in children with cerebral palsy (Myhr and von Wendt 1990, 1991; Myhr et al 1995. Children with neuromotor and neuromuscular dysfunction will require external support from seating systems to accommodate for compromised postural control and postural deficits. Based on clinical and empirical evidence, it is accepted that the general goals of seating and positioning include the following, and will be considered in the context of this review: 1) Normalise tone or decrease abnormal influence on the body. 2) Maintain skeletal alignment. 3) Prevent, accommodate or correct skeletal deformity. 4) Provide stable base of support to promote function. 5) Promote increased tolerance of desired position 6) Promote comfort and relaxation. 7) Facilitate normal movement patterns or control abnormal movement patterns. 8) Manage pressure or prevent the development of pressure sores. 9) Decrease fatigue 10) Enhance autonomic nervous system function (cardiac, digestive and respiratory function) 11) Facilitate maximum function with minimum pathology. (Jones and Gray 2005).
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Seating and Positioning: Principles and Practice Normal Posture Following a review of the literature, it is difficult to define what constititutes ‘normal’ posture. This is because each person is unique regarding their physiological profile and continually engages in a number of postural variations which may be attributed to fatigue and emotional state (Howe and Oldham 2001). From a biomechanical viewpoint, good posture is dependent on the balance of the skeleton and symmetrical alignment of body segments. Engström (2002) states that those who balance their body in accordance with mechanical rules for human body systems (laws of physics) tend to be more erect. From a neurophysiological and developmental perspective, normal posture is also dependant on the development of normal postural control which is described as the control of the body’s position in space in order to obtain stability and orientation (Brogren et al 1998) and is influenced by the neuromotor, somatosensory, vestibular and musculoskeletal systems (Nichols 2001). Postural control requires achieving normal developmental milestones and includes the development of postural reactions (righting, protective and equilibrium reactions), developmental integration of primitive reflexes (asymmetrical tonic neck reflex, symmetrical tonic neck reflex, tonic labyrinthe reflex), normal muscle tone, normal postural tone and intentional voluntary movements (Wandel 2000).
The action of sitting It is also useful to understand the interface between the standing and seated posture. Turner (2001) suggests the ‘action of sitting’ results in flexion of the thoracic spine, flexion of the lower extremities, and backwards rotation of the pelvis towards the rear of the seat. Pelvic rotation in turn dictates the compensatory curves of the spine, which in turn dictates the position of the remaining body segments (Harms 1990). The pelvis is then placed on the seat against the backrest. The trunk extends, moving towards the backrest. The upper part of the pelvis is in contact with the lower part of the backrest, thus achieving pelvic stability, with the person now sitting in an upright neutral position.
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Neutral sitting posture Sitting skills emerge in a normally developing child approximately between 7
and 9 months and requires the child to maintain postural control of the head, trunk and extremities against the pull of gravitational forces (Wandel 2000). The majority of the literature refers to the 90-90-90 position as the normal upright neutral seated posture and considers the head, trunk and extremity positions in relation to each other. Assuming that one is sitting on a flat, right angled chair in a static or neutral position, the upright symmetrical position is characterised by extension of the trunk, the pelvis in anterior tilt, thighs slightly abducted, parallel and horizontal and the iliac crests aligned and level in the lateral plane (Ham et al 1998). The hips, knees and ankles are placed at ninety degrees of flexion, the feet are in plantar grade or 0° degrees flexion (Green and Nelham 1991) and the head is positioned in midline and maintained in the vertical plane (Erhardt and Merril 1998). The head position in relation to the spine is important as it has a direct effect on posture. Loss of head control can therefore affect body position (Ham et al 1998). When the pelvis is in anterior tilt, the centre of gravity falls anterior to the ischial tuberosities (Ham et al 1998) hence the base of support is provided through the ischial tuberosities and the upper thighs (Howe and Oldham 2001). Depending on the chair design, weight will be transferred through the back rest, and the arm rests to the floor through the feet (Pynt et al 2001). The goal of upright positioning is therefore to promote symmetry and alignment of the body segments and linkages (Ham et al 1998). The sitting position is more relaxing than the standing posture, provides a greater support surface and allows relaxation of the muscles of the lower extremities (Howe and Oldham 2001). However, there is greater potential for pelvic instability in sitting compared to standing due to the hip joint position, the anatomical shape of the ischial tuberosities (Reid and Rigby 1996) and the tendency for the pelvis to rotate backwards (Engström 2002).
In the seated posture, it is desirable that as much contact is made with the chair’s support surface in order to provide maximum stability to facilitate function (Green and Nelham 1991), with the goal of seating being able to achieve a stable base of support surface to allow function (Jones and Gray 2005). However in right angled seating, it is difficult to achieve and often results in a person acquiring a ‘slumped’ posture to compensate for fatigue and discomfort. Combined with the effects of constant activation of the erector spinae muscles, a person will gain relief from excessive muscle activity by sacral sitting, resulting in posterior rotation of the pelvis, accentuation of thoracic kyphosis and cervical lordosis, loss of lumbar lordosis of the spine (Pynt et al 2001) and increased risk of tissue trauma in the sacral area (Han et al 1998). A further goal of seating is to prevent or decrease the occurrence of pressure sore development (Jones and Gray 2005). Conflicting opinion exists regarding the causation of posterior pelvic tilt. Some authors postulate that the tendency for the pelvis to rotate posteriorly may be due to tension in the hamstrings and gluteal muscles which promotes flexion of the lumbar spine hence inducing posterior rotation of the pelvis. (Mayall and Desharnais 1995; Trefler and Taylor 1991; Pynt et al 2001; Effgen 2005). Contrary to opinion Engström (2003) attributes the tendency of thoracic spine collapse (flexion) as influencing the backward rotation of the pelvis and suggests that seating interventions should aim to improve thoracic extension to block
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flexion of the spine. Engström (2002) suggests that backward inclination induces flexion of the thoracic spine whereas a forward inclined seated position promotes thoracic extension. A study conducted by Miedaner (1990) investigating the effects of sitting positions on trunk extension for children with motor impairment supports this assumption. Miedaner concluded that anterior sitting (20° and 30° inclined) compared to level bench or floor sitting increased trunk extension, as measured by the modified Schoeber Measurement of Spinal Extension (AAOS 1975). Using a randomized complete block design a significance level of p=0.001 demonstrated a true mean difference between the different sitting positions, however small sample size limits the generalisability of this finding. The 90-90-90 Position – How Useful?
The 90-90-90 position may be regarded as an ideal seated position from an
ergonomic perspective (Engström 2001). From an anatomical view point the goal is to achieve maximum orthopaedic symmetry between left and right sides of the body via a neutral pelvis to avoid obliquity, rotation and posterior pelvic tilt (Lange 2001). Advantages of this position depicted in the literature include minimisation of orthopaedic deformity (Ham et al 1998) and promotion of proximal stability which in turn promotes distal control (Lange 2001). One of the goals of seating is to promoted relaxation and comfort (Jones and Gray 2005). Kangas (2002) suggests the 90-90-90 position can passively and temporarily reduce tone when considered as a resting position. Two studies identified support for this assumption.
Nwaobi et al (1983) conducted a study using electromyography (EMG) to
investigate the activity of extensor muscles of the lumbar spine in children with cerebral palsy in different seating positions. Seat surface inclinations of 0° and 15° combined with backrest inclinations of 75°, 90°, 105° and 120° provided the testing conditions. Results concluded that electrical activity was least when seat surface elevation was 0° and backrest inclination was 90°. Caution is advised in generalising results as testing positions were based on EMG activity recording 60 seconds of sitting in each position and on a small sample of eleven subjects. A subsequent study conducted by Nwaobi (1986) regarding the effects of body awareness in space on tonic muscle activity of patients with cerebral palsy concluded that muscle activity was lower in the upright position (90-90-90) than the reclined position (30° from vertical plane), with statistically significant results obtained for back extensors and hip adductors (p=0.05). One of the goals of seating is to promote increased tolerance in the desired position (Jones and Gray 2005). Findings from this study suggest that extensor tone is increased in the reclined position.
Literature also identifies that the 90-90-90 position is difficult to maintain over
time (Ham et al 1998; Howe and Oldham 2001) and may impede function (Engström 2002). One study however concluded that the upright position was more functional in comparison with anterior and posterior sitting positions. Nwaobi (1987) investigated seat orientation of upper extremity function in thirteen children with cerebral palsy (spastic and athetoid) and concluded that arm movements were significantly faster
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when positioned in 90-90-90 compared to anterior (15°) and posterior (15° and 30°) orientations. The authors attribute this outcome to either improved control of or decreased abnormal neuromuscular activity in the upright position. The authors also consider loss of horizontal eye contact and greater effort required to counteract gravitational effects in the posterior orientation as impeding upper extremity function (Nwaobi 1987). Other studies identified compare the upright neutral position to alternative sitting positions e.g. inclined/reclined seat base, inclined/reclined back rest, and their relationship to function. Findings from studies examining the effects of seat inclination on upper extremity function are mixed. Some authors (Mhyr and von Wendt 1990, 1991, Myhr et al 1995) concluded that anterior sitting in the ‘functional sitting position’ improved upper extremity function in children with neuromotor dysfunction. Other research studies report no effects on upper extremity function with regard to seat inclination (McClenaghan et al 1992) and no effects regarding anterior tipped seating on respiratory function in children (Reid and Sochaniwskyj 1991). These studies will be reviewed in the next section.
Several authors advocate the idea of bypassing the 90-90-90 position. Kangas
(2002) argues that for functional performance, movement and tone are required, but the 90-90-90 position prevents functional performance as it is essentially a resting position and too restrictive. Minkel (2001) postulates that the goal of adapted seating should extend beyond achieving perfect symmetry, but should focus on providing external support, at the angles needed by an individual to achieve an upright, stable and functional position. It is recognised that ideology based on expert opinion and experience provides important information which may be added to a growing evidence base however caution must be exemplified when using anecdotal evidence to justify practice. Shimizu et al (1994) acknowledges that deviation from the optimal upright position is often required to accommodate for fixed deformities and abnormal postural tone, yet basic positioning principles should be maintained. This is to provide equal distribution of weight, for support, stability and comfort. It may be derived that the 90°/90°/90° position is a useful baseline position to achieve to promote symmetry with further seating adaptations / components being utilised to facilitate function.
Functional Sitting Position A major goal in seating is to provide and stable base of support to promote function and to enhance autonomic nervous system function (Jones and Gray 2005). Pain et al (2003) suggests that alternative sitting positions to 90-90-90 are being proposed and include forward inclination to permit engagement in functional tasks and backwards recline for relaxation. Findings from studies regarding the effects of seat inclination on function and/or postural control are conflicting. Studies identified for review, focus on the cerebral palsy population and/or typically developing children. Several authors suggest that forward inclination promotes improved upper
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extremity function (Myhr and von Wendt 1991, Myhr et al 1995; Reid 1996); trunk extension (Miedaner 1990) and improved postural efficiency (van der Heide 2003, Myhr and von Wendt 1990, 1991). Other research studies report no effects of anterior tipped seating on respiratory function (Nwaobi and Smith 1986, Reid and Sochaniwskyj 1991, Redstone 2004); upper extremity function (McPherson et al 1991; McClenaghan et al 1992) and postural stability (McClenaghan et al 1992). Myhr and von Wendt (1991) conducted a study to find a functional sitting position for children with cerebral palsy. Twenty-three children were photographed and video filmed in six different sitting positions, including the functional sitting position (FSP). The FSP required the pelvis to be anteriorly tilted, with the upper body anterior to the fulcrum at the ischial tuberosities to allow an upright posture. Symmetrical weight bearing through the ischial tuberosities was achieved via fixation of hip belt at 45° angle and use of abduction orthoses. Results suggested that the functional sitting position in comparison to the children’s original sitting position minimised pathological reflexes, improved postural control and improved upper extremity function when children sat in forwards inclination (mean 8°, range 0° to 15°), with a firm back rest supporting the pelvis and supported by a cut out level table to eliminate lateral sway imbalance. Results support previous preliminary findings investigating the FSP and its impact on reduction of spasticity and enhancement of postural control (Myhr and von Wendt 1990), although seat inclination alone showed no identifiable effects, it is subjectively suggested that anterior tilting may stretch the hamstring muscles when the pelvis is rotated forward hence reducing spasticity. This is assuming the feet are secured and fixed and the lower extremities are not permitted to flex under the thighs, however the authors do not provide a specific description regarding the exact positioning of the feet. A five year follow up study investigating ten children with cerebral palsy (Myhr et al 1995) concluded that the FSP contributed to significant improvement (p> 0.05) in head, trunk and foot control and upper extremity function in eight of the ten children as assessed by the Sitting Assessment Scale (Myhr and von Wendt 1991). A study conducted by Reid (1996) utilising a repeated measures experimental cross over design compared the effects of level or flat benched seating versus saddle-benched seating (15° anterior tilt) on postural control and reaching motions of six children with cerebral palsy assessed by the Sitting Assessment for Children with Neuromotor Dysfunction (Reid 1995). Small sample size rendered insufficient power analysis to detect statistically significance differences, however group results and single subject data analysis suggest that saddle sitting may potentially improve postural and reaching movements. An investigation regarding the development of postural adjustments during reaching in twenty-nine typically developing children, and ten adults (van der Heide et al 2003) suggested that forward tilted seating (15° seat surface inclined) was a more efficient position for postural efficiency compared to horizontal (0°) and backwards tilted (15° seat surface reclined) sitting positions. Findings were contrary to the original hypothesis postulated by the authors, who hypothesised that backward sitting would have been the most efficient position as it would passively counterbalance the forward body sway induced by reaching movements. Sitting positions were studied via surface Electromyograms (EMG) and kinematics, therefore quantifying results.
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Miedaner (1990) investigated the effects of sitting positions on trunk extension in fifteen children with motor impairment (cerebral palsy) using the modified Schober Measurement for Spinal Extension. As previously discussed, results suggested that the anterior sitting (20° and 30° inclined) tend to increase trunk extension compared to level bench or floor sitting. Subjective observations suggest that upper extremity function is not compromised despite increased muscle activity required to maintain trunk extension when the seat is tilted forward. Further EMG analysis of spinal muscle activity regarding trunk extension would objectify results. Contrary to these findings other authors conclude that seat inclination has no discernable effects. McClenaghan et al (1992) investigated the effects of seat surface inclination on postural stability and function of the upper extremities of children with cerebral palsy. Twenty children (ten non-impaired; ten mild cerebral palsy) were included in the study, with seat surface inclinations depicted as 0° horizontal, 5° anterior tilt, and 5° posterior tilt, with seat to back inclination maintained at 90°. Previous authors (Myhr and von Wendt 1990, 1991; Miedaner 1990; Myhr et al 1995; Reid 1996; van der Heide 2003) used seat surface inclinations of greater than 5° (range 8°- 30°); however McClenaghan justifies 5° inclination by stating that greater tilting is difficult to tolerate for an extended period with this assumption based on pilot investigations. Previous research has shown that lumbar spine muscle activity increases when the seat is tilted forward (Nwaobi 1987).
McClenaghan et al (1992) concluded that significant between-group differences were observed on most dependent measures (p>0.05) however, suggested that anterior tilt seating in cerebral palsied children may actually disturb postural stability, without improving performance of the upper extremities and suggested posterior tilt as a more efficient position during periods of upper extremity function. Although only applicable to the adult cerebral palsy population, McPherson et al (1990) also concluded that no significant differences could be attributed to seat inclinations regarding upper extremity movement. Hadders et al (1999) when conducting a study to investigate the development of postural adjustments in reaching in infants in children with cerebral palsy also favoured the reclined position (semi-recline at 45°) as opposed to lying in supine, long leg sitting and upright sitting). McClenaghan (1992) also argues that the use of a table in Myhr and von Wendt (1991) study may result in weight bearing on the support surface, which in turn actually impedes the use of the upper extremities for function. This would hinder the carrying out of bilateral activities. Similar findings have been reported regarding the effects of seat inclination on respiratory function. Redstone (2004) investigated the respiratory patterns in upright and semi-reclined seating positions in ten preschool children with cerebral palsy and ten typically developing children. No significant differences could be attributed to seat position alone. Reid and Sochaniwskyj (1991) conducted a study to investigate the effects of anterior tipped seating on respiratory function of normal children and children with cerebral palsy. Twelve subjects (six normal; six cerebral palsy) were compared in level (0°) and anterior tipped (10° seat surface inclined) seating, with respiratory function measured by respitrace transducers. No significant differences in respiratory function could be attributed to seat inclination alone either in the normal or cerebral palsy groups, however it is recognised that a larger sample size may have
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yielded greater power analysis to detect statistical significance. Nwaobi and Smith (1986) in an earlier study investigated the effect of adaptive seating on pulmonary function of eight children with spastic cerebral palsy, and concluded that pulmonary function was more efficient when children were positioned in adaptive seating in the upright (90-90-90) position. Continued disparity in the literature exists regarding the direction of seat inclination for improved function and postural control. Studies reviewed used small sample sizes, lacked power analysis, and used various seat inclination values and different assessment times in seated positions and short periods of data analysis therefore making comparisons difficult. Additionally some studies do not refer to cerebral palsy as a heterogeneous group. Selection bias was also evident in some studies therefore questioning the reliability of the findings. Future research should utilise larger sample sizes and to aid power estimates so that results may be generalisable to the sample population.
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FACTORS AFFECTING POSITIONING Children with neuromotor / neuromuscular dysfunction will have compromised postural control. This section discusses postural problems and how they can affect positioning and possible seating solutions that accommodate or prevent further deviation from normal posture; however consideration regarding the effectiveness of seating components and their functional use are beyond the scope of this report. The problems depicted in the literature include a) retention of primitive reflexes; b) presence of structural asymmetries c) abnormalities of muscle tone. a) Primitive Reflex Activity Ø Asymmetrical Tonic Neck Reflex Ø Symmetrical Tonic Neck Reflex Ø Tonic Labyrinthine Reflex Ø Positive Supporting Reaction Ø Moro Reflex
Asymmetrical Tonic Neck Reflex (ATNR) According to Ham et al (1998) ATNR is elicited when the head is turned to one side. The reflex is characterised by increased extensor tone on the side to which the head is turned and increased flexor tone on the opposite side. This reflex is usually integrated between 4-6 months (Lowman 2000). According to Hong (2005) the continued presence of ATNR after 4-5 months is considered abnormal and interferes with rolling, bilateral integration, reaching and grasping activities. Due to the tendency of children to use one hand, continued repetitive movements may lead to the development of scoliosis (Ham et al 1998). Extensor postures (Levitt 2004), soft tissue balance and asymmetries in muscle tone may also lead to secondary deformities including subluxed hips and, contractures mainly affecting the hip flexors and adductors (Hong 2005). Symmetrical Tonic Neck Reflex (STNR) STNR is elicited when the head is flexed or extended (Lowman 2000). According to Ham et al (1998) when the head is flexed, the upper extremities flex and the lower extremities extend. When the head extends, the upper extremities extend and the lower extremities are pulled into flexion. This reflex is normally integrated
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between 4-6 months. Retention of STNR interferes with reciprocal creeping, walking (Lowman 2000) and upper limb function (Ham et al 1998.) Tonic Labyrinthine Reflex (TLR) TLR is elicited when in supine or being moved into flexion or extension (Lowman 2000). In supine or with the head extended, there is increased extension throughout the body. In prone or when the head is forward of the upright position, there is an increase in flexion throughout the body (Ham et al 1998). This reflex is usually integrated between 4-6 months. Retention of TLR interferes with side turning, rolling, and lying to sitting ability and creeping (Lowman 2000). Positive Supporting Reaction The positive supporting reaction is elicited when infants are supported under the shoulders and held upright with feet flat on the floor (Ham et al 1998) Proprioceptive stimuli via the feet induce extension of the lower extremities and plantar flexion of the feet (Lowman 2000). This response is usually integrated between 1-2 months and disappears when the child learns to weight bear through feet and stand independently (Ham et al 1998). Retention of this response will interfere with walking patterns and may lead to walking on toes (Lowman 2000). In addition, Ham et al (1998) suggest that proprioceptive stimuli applied to the intrinsic muscles of the feet when pushing down on foot rests can also elicit an extensor thrust, which can lead to sacral sitting and the development of extension contractures of the hip. Moro Reflex Ham et al (1998) suggest the Moro reflex is elicited when the head extends backwards, which results in an extension pattern of the body, with the arms extended, abducted and externally rotated followed by a flexion posture. This reflex is normally integrated between 4-6 months and if retained, interferes with head control, sitting equilibrium and protective reactions (Lowman 2000), all of which are needed for postural control. Seating Interventions
Goals of seating include normalising tone or decreasing abnormal influences on the body and to facilitate normal movement or pathological activity (Jones and Gray 2005). Although Wright-Ott and Egilson (2001) suggest that tilt in space may provide a child with hypotonia (low muscle tone) with greater tolerance for upright sitting, other authors suggest that tilt in space and/or reclined sitting may
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increase pathological reflexes (Nwaobi et al 1983; Nwaobi 1986; Myhr and von Wendt 1990, 1991, Mhyr 1994; Engström 2002). As previously discussed, Nwaobi (1986) concluded that children with cerebral palsy have better postural control in the upright rather than the reclined or tilted position. In testing conditions Nwaobi (1986) found that increased extensor tone resulting from TLR was elicited by the position of the head in the reclined position, adding that loss of horizontal eye contact resulted in a greater effort to overcome gravity and consequently increased tone. This study also highlighted that asymmetry of muscle activity in back extensors and prolonged seating in the reclined position may contribute to development of a scoliosis. Ham et al (1998) also suggest that tilting of a seat and reclining the backrest can affect eye contact, as well as upper extremity function and spinal posture. Tilting may therefore reduce functional ability to participate or interact with others and the environment. Similarly Myhr and von Wendt (1990) in their pilot study concluded that the backward tilted position was the most inefficient position to reduce spasticity and enhance postural control. Pathological reflex activity increased considerably in the tilted position. Twenty-two ATNR movements were recorded in the tilted position compared to one ATNR when in the functional sitting position. Myhr and von Wendt (1991) support these findings when investigating the functional sitting position in children with cerebral palsy. Findings suggest that pathological movements were significantly reduced (p=0.001) in the functional sitting position compared to backward tilting. Herman and Lange (1999) suggest that the head should be kept close to mid line to avoid active neck rotation which may elicit an ATNR. Levitt (2004) suggests that therapists prevent extensor patterns and subsequently chair sliding by using tilt in space with hips flexed between 95° and 110°, although adds that it is not a suitable position for those displaying the Moro response, head and trunk thrust in semi lying or increased athetosis. Engström (2002) postulates that a constant tilt in space position may contribute to development of extensor patterns in the cerebral palsy population and suggests that the trunk’s position in space may change the extensor pattern. Engström suggests that an individual contoured seating unit which is forward tipped may be beneficial and highlights that dynamic seating systems may be beneficial as they enable a change of position between upright and rest. b) Structural Asymmetries Ø Spinal deformity (lordosis, scoliosis, kyphosis) Ø Pelvic Tilt Ø Windswept deformity / Hip dislocation
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Spinal deformity: Lordosis Lordosis may be defined as an anteroposterior curve of the lumbar spine in which the concavity is directed posteriorly (Rodgers et al 2001). In normal posture the lumbar spine should be slightly hollow or lordosed, however muscle imbalance may result in excessive lengthening and weakening of the abdominal and gluteal muscles and tightening of the iliopsoas and spinal erector muscles which results in the pelvis being tilted anteriorly and further increasing the curvature of the lumbar spine. This results in a lordotic posture (Howe and Oldham 2001). Lordosis may be secondary to other spinal deformities, anterior pelvic tilt, hip flexion contractures and is also associated with muscular dystrophy. Treatment usually centres on managing underlying problems and includes stretching tight hip flexors, strengthening abdominal muscles and in severe cases bracing may be required (Rodgers et al 2001). Scoliosis Scoliosis is a lateral curvature of the lumbar and/or thoracic spine often accompanied by axial rotation of the vertical bodies (Howe and Oldham 2001). The Scoliosis Research Society defines scoliosis as a lateral curvature exceeding 10° using the Cobb method (Scoliosis Research Society 2002). According to Rodgers et al (2001) curves of less than 20° are mild, curves over 40° result in permanent deformity and curves of 65° and over may result in compromised cardiopulmonary function. The development of scoliosis has been associated with asymmetrical muscle tone (Young et al 1998), retention of primitive reflexes (Ham et al 1998), poor postural tone, hip contractures (Rodgers et al 2001) and compensatory postures resulting from leg length discrepancy or abnormal pelvic tilt (lateral tilt, obliquity and rotation) (Howe and Oldham 2001), and increased interface pressure when sitting (Shoham et al 2004). Scoliosis occurring in combination with pelvic obliquity and hip deformity is usually convex to the side opposite the dislocated hip and pelvic obliquity (Gudjonsdottir and Stemmons Mercer 1997). It is recognised that scoliosis is generally progressive and can contribute to a number of secondary health problems such as positional pain, respiratory compromise, pressure sores and loss of function (Holmes et al 2003). Scoliosis may be described as fixed or structural meaning that there is permanent deformity which cannot be altered by posture, with the vertebral bodies rotating towards the convexity of the curve and the spinal processes towards the concavity of the curve (Howe and Olham 2001). In extreme cases, surgical intervention may be considered. A flexible scoliosis may be passively or actively corrected via non-surgical intervention including spinal jackets and specialised seating (Holmes et al 2003).
The literature suggests that management of scoliosis is achieved via a three point force system to the sides of the body. Ham et al (1998) suggests the use of lateral supports, which involves forces acting from anterior to posterior at the pelvis, anterior to posterior at the shoulders and posterior to anterior at the apex of the kyphotic (flexible) spine. A study conducted by Holmes et al (2003) investigating the effects of special seating on lateral spinal curvature in the non-ambulant spastic cerebral palsy population supports this assumption. Holmes et al (2003) concluded that significant static correction of the scoliotic spine can be achieved by a three point force arrangement of lateral pads to the sides of the body.
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Shoham et al (2004) investigated the influence of seat adjustment and a
thoraco-lumbar-sacral orthosis (TLSO) on the distribution of body seat pressure in fifteen children with scoliosis and pelvic obliquity. Seat adjustments included either the use of either elevation of the lower side of the pelvis or a wedge insertion beneath the raised pelvis. Results concluded that the TLSO significantly reduced the spinal curvature and interface sitting pressure (p<0.05), however seat adjustment had no significant effect on pressure distribution. Kyphosis
Kyphosis is characterised by an increased posterior curvature (‘C-shaped’) of the thoracic spine (Howe and Oldham 2001). The kyphosed posture is apparent during sacral sitting, with the pelvis posteriorly tilted and the thoracic spine in flexion (Ham et al 1998). Ham et al (1998) further add that a sling back seat and back support can accentuate kyphosis. The development of kyphosis may be associated with poor posture, weak erector spinae muscles (required for trunk extension), compensation to hip deformity (Howe and Oldham 2001), and also occurs in children with cerebral palsy who demonstrate extensor spasticity in the lower extremities due to tight hamstrings (Ham et al 1998). Head position is then affected, resulting in forward flexion or head drop. In order to compensate for head dropping, the individual will hyperextend their neck in order to visually interact with the environment, however this will compromise respiratory and swallowing function (Herman and Lange 1999). Engström (2002) suggests additional problems include neck pain, flexion contractures of the trunk muscles, restricted arm movement and increased abdominal pressure.
Several authors (Trefler and Taylor 1991; Ham et al 1998; Engström 2002;
Levitt 2004) suggest tilt in space or opening the seat to backrest angle to accommodate or support a kyphosis. Engström (2002) suggests the seating unit should be contoured for equal pressure distribution and the backrest is reclined, although does not an angle at which recline should occur. Trefler and Taylor (1991) also suggest the use of a custom contoured back support with a flexible anterior harness, adding that individuals with a 30° or greater scoliosis may require reclined seating to accommodate or correct the curve. Tilt in space may also be considered as it may reduce the effects of gravity acting on the upper body, with the weight of the body being taken through the backrest (Ham et al 1998, Pope 2002). However, the advantages of tilting must be considered against the loss of function. Pelvic Tilt Posterior pelvic tilt is a major problem in seating as it compromises pelvic stability (Engström 2002). Problems associated with posterior pelvic tilt include flattening of lumbar curve, accentuation of thoracic kyphosis (Pynt et al 2001) sacral sitting, and increased risk of pressure sore development at sacral / coccygeal area (Ham et al 1998). Causation of posterior of pelvic tilt is attributed to the tension in
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the hamstrings (Mayall and Desharnais 1995; Trefler and Taylor 1991; Ham et al 1998; Pynt et al 2001) or by flexion of the thoracic spine (Engström 2002). Effgen (2005) suggests when a child has tight hamstring muscles, footrests must angle under the seat to accommodate for tightness and allow the pelvis to remain stabilised. Seating solutions utilize anterior pelvic stabilisation devices to maintain the pelvis in anterior tilt to prevent backward rotation (Reid and Rigby 1996). Approaches used include ramped cushions (15° inclined) in conjunction with a pelvic belt, sacral pad, knee blocks and foot support (Green and Nelham 1991). Straddle seating (Reid 1996), firm back rests and use of an anterior superior iliac spine padded bar acting on the ischial tuberosities (Ham et al 1998), and anterior tipped seating combined with use of hip belt and abduction orthosis (Myhr and von Wendt 1990, 1991, Mhyr et al 1995) are other methods used to achieve pelvic stabilisation. Windswept Deformity Windswept hip deformity is an abduction contracture of one hip resulting in an adduction contracture of the contralateral hip and may be associated with pelvic obliquity and secondary scoliosis (Young et al 1998). Pelvic obliquity results in pelvic rotation in the transverse plane and pelvic tilt in the saggital plane (Gujonsdottir and Mercer 1997). Aetiology of windswept deformity is unknown; however contributing factors include acetabular dysplasia, femoral anteversion, spasticity, retention of ATNR (Reese et al 1990), muscle imbalance and hip contractures (Young et al 1998). Seating interventions may utilise a knee block system to help correct windswept hips (Levitt 2004). According to Ham et al (1998), the knee blocks should be adjusted so that a force is applied anterior to posterior, via the abducted femur, to the pelvis on the side that is rotated anteriorly. This is in addition to the use of lateral supports and a sacral pad to help de-rotate the pelvis. Trefler and Taylor (1991) suggest positioning in abduction may discourage the tendencies of adduction of both hips via the use of a pommel. Structural deformity of the hip joint is a major problem in seating. Developmental Dysplasia or Congenital Hip Dislocation will be explored in greater depth in the childhood diseases section of the report. c) Abnormal Muscle Tone Normal muscle tone refers to the ability of muscles to maintain the correct amount of tension and elasticity during movements (Wandal 2000) and may be defined as resistance to passive elongation or stretch (Harris 1991). Abnormalities of muscle include hypotonicity, hypertonicity or fluctuating tone (Hong 2002) and have been associated with deficits in postural control (Nichols 2001). Hypotonia is
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characterised by decreased muscle tone and results in muscles appearing lax and floppy (Kohlmeyer 1998) with functional movement and muscle endurance compromised (Reed 2001). Decreased muscle tone can contribute to the development of kyphosis or lordosis with increased hip flexion, lower limb contractures (Ham et al 1998), joint immobility, instability and subluxation due to large range of movement (Hong 2002), weakness, hyperextended knees and valgus or flat feet (Levitt 2004). Hypertonicity or spasticity is characterised by increased tension or contraction in the muscles (Ham et al 1998). Increased muscle tone may also contribute to scoliosis, muscle contractures, extensor/flexion synergies (Ham et al 1998), clonus, hyperreflexia (exaggerated stretch reflex) patterns (Reed 2001) and persistent primitive reflexes (Erhardt and Merill 1998). Hong (2002) highlights that hypotonicity and hypertoncity often present simultaneously. This is illustrated in the cerebral palsy population whereby the child may exhibit a hypotonus trunk, rendering trunk extension difficult, yet present with hypertonicity of the extremities (Westcott and Goulet 2005). Research has highlighted that spasticity is decreased when the hips are flexed (Nwaobi et al 1983). Nwaobi et al (1983) also found that in addition to the influence of hip flexion, orientation of the body contributed to controlling extensor muscle tone. As previously discussed, this study concluded that spasticity in the lumbar area was lower in the upright position (90°/90°/90°), compared to a backward tilted position. Nwaobi (1986) also concluded that tonic muscle activity of the back extensor and hip adductor muscles were significantly lower (p=0.05) in the upright position compared to recline. Myhr and von Wendt (1990) suggest that stretching spastic hamstring muscles can only be achieved by rotating the pelvis anteriorly, with a straight back. Research has evidenced enhanced postural control via the use of the functional sitting position which puts the pelvis into anterior tilt (Myhr and von Wendt 1990, 1991; Myhr et al 1995, van der Heide 2003).
Based on expert opinion, Herman and Lange (1999) suggest that knee flexion past 90° and ankles in dorsiflexion with slight eversion may reduce extensor spasticity. Empirical evidence suggests that dynamic seating components may also accommodate and reduce tone and enhance function (Cooper et al 2001). This evidence suggests that accommodating abnormal movement and gently returning the limb to normal alignment is more beneficial than blocking the movement. Some authors suggest that tilt in space may be required if the child has hypotonus in order to counteract the effects of gravity (Wright-Ott and Egilson 2001; Ham et al 1998; Pope 2002) yet highlight that advantages of tilt in space must be considered against loss of function.
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CHILDHOOD CONDITIONS Ø Cerebral Palsy Ø Congenital Hip Deformity / Developmental Dysplasia Ø Rett Syndrome Ø Duchenne Muscular Dystrophy Ø Spina Bifida
Cerebral Palsy According to Rodgers et al (2001), Cerebral palsy may defined as a non-progressive abnormality of the developing brain that results in neurological, motor and postural deficits in the developing child. Perceptual, cognitive, sensory and psychosocial dysfunction may also co-exist with this disorder (Ham et al 1998). Classification of cerebral palsy may be according to topographical distribution (monoplegia; diplegia; hemiplegia; paraplegia; tetraplgia or quadriplegia), quality of tone (hypotonia or spasticity; hypertonia; athetosis; ataxia), degree of involvement (mild; moderate or severe) and locality of the brain lesion (Westcott and Goulet 2005). It is reported that the incidence rate of cerebral palsy is approximately 2:1000 live births (ref) and may be attributable to pre-natal, perinatal and post-natal factors (Erdhardt and Merril 1998). Reed (2001) describes four main groups of cerebral palsy syndromes: Spastic This type displays increased muscle tone resulting from an upper motor neuron lesion, ranges from mild to severe and is categorised according to the part of the body affected. Erdhardt and Merril (1998) state that spasticity is also accompanied with persistent primitive reflexes, clonus and hyperreflexia and results in difficulty with gross and fine motor control. Athetoid / Dyskinetic This results from basal ganglia dysfunction and is characterised by slow, jerky, writhing involuntary movements which may affect the extremities (athetosis) or proximal parts of the trunk and limbs (dyskinesis). Athetosis or fluctuating tone results in tone rapidly shifting from normal or hypertonic to hypotonic or low tone (Wandall 2000). It is suggested that athetoid movements are exasberated by emotional disturbance (Ham et al 1998; Reid 2001; Westcott and Goulet 2005) and decreased by prone lying, fatigue or increased concentration (Ham et al 1998). Ataxic This results from cerebellar dysfunction and is characterised by weakness, incoordination, intention tremor, unsteady wide based gait, difficulty coordinating fine motor skills (Reed 2001) and difficulty maintaining stable alignment of the head, trunk, shoulders and pelvis Wandall (2000). According to Ham et al (1998) a child with ataxic cerebral palsy is at greater risk of developing scoliosis than those with spastic diplegia or hemiplegic cerebral palsy.
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Clinical Manifestations In addition to motor impairment, a multitude of clinical problems co-exist with cerebral palsy and include cognitive and learning disabilities (Ham et al 1998); sensory deficits including hyperresponsivity or hyporesponsivity (Erhardt and Merril 1998) proprioceptive, visual and vestibular dysfunction (Westcott and Goulet 2005); epilepsy (Hare et al 1998); hydrocephalus (McDonald et al 2004); behavioural disturbances (Ham et al 1998); oral motor dysfunction due to retention of primitive reflex activity affecting eating and swallowing ability (Erdhardt and Merril 1998); gastro-oesophageal reflux and speech and language difficulties (McDonald et al 2004). This report focuses on the musculoskeletal impairments of body segments associated with cerebral palsy. SPINE
Literature suggests that children with cerebral palsy are likely to develop spinal deformity (scoliosis, thoracic kyphosis and lordosis) with the highest incidence occurring in individuals with spastic quadriplegia (Gudjonsdottir and Stemmons Mercer 1997). Research has evidenced that there is a correlation between tight hamstrings and hypolordosis in children with cerebral palsy (McCarthy and Betz 2000). Additional contributing factors to spinal deformity include decreased stability and asymmetrical posture (Westcott and Goulet 2005), primitive reflex activity (Ham et al 1998), atypical muscle imbalance, tone and weight bearing (Gudjonsdottir and Stemmons Mercer 1997), leg length discrepancy and pelvic obliquity (Howe and Oldham 2001). Consequences of spinal deformity include decreased range of movement, positional pain, and functional limitations. PELVIS According to Lowes and Orlin (2005) pelvic abnormalities in cerebral palsy include obliquity, posterior and anterior rotation. The relationship between tight hamstrings and hypolordosis may also contribute to the posterior rotation of the pelvis. HIP Hip displacement (dislocation or subluxation) is a major disability in cerebral palsy and can cause difficulties in sitting, positioning (Hankinson and Morton 2002), ambulation and perineal hygiene (Scrutton et al 2001). According to McDonald et al 2004) hip displacement is measured by the migration of the head of femur away from the acetabulum, with hip subluxation exceeding 33% migration and hip dislocation exceeding 80% migration. Aetiology is unknown however; contributing factors include persistence of ATNR, acetabular dysplasia, hypertonicity, hip contractures, decreased ambulation and muscle imbalance. Research evidence suggests that children with tonal asymmetry and severe spasticity appear to be at increased risk of dislocation, with a windswept deformity on the opposite side (Young et al 1998).
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Pountney et al (2001) support this assumption by stating that imbalance in muscle strength and length around the hip leads to dysplasia and subsequent hip subluxation. Gudjonsdottir and Stemmons (1997) suggest that an important predictor in hip stability is the age at which a child is able to pull to stand. Cornell (1995) reported that less than 2% of children who are able to pull to stand before the age of three years have hip subluxation or dislocation. Hip dislocation, pelvic obliquity and scoliosis are related problems in cerebral palsy (Gudjonsdottir and Stemmons Mercer 1997), with Letts et al (1984) reporting that dislocation occurs first, followed by obliquity, then scoliosis. Research has evidenced that postural management interventions have an important role in preventing dysplasia of the hip in children with cerebral palsy (Pountney et al 2001). A retrospective study of 59 children with bilateral cerebral palsy concluded that children using all Chailey Adjustable Postural Support Systems (CAPS) maintained significantly more hip integrity (p<0.05) compared with other groups. FOOT / ANKLE Lowes and Orlin (2005) suggest that impairments of the foot and ankle include reduced dorsiflexion resulting from shortened gastrocnemius, plantar flexion during weight bearing resulting from hypertonicity and ankle instability and the acquisition of a flat foot position due to breakdown of the arch of the foot resulting from decreased weight bearing ability. Seating and Postural Implications
Children with cerebral palsy will have difficulty with stationary postures, transitionary movements and functional mobility (Westcott and Goulet 2005). Literature suggests that appropriate seating should aim to normalise tone, inhibit reflex activity, prevent deformity, promote optimal function, maintain postural alignment, maintain tissue integrity and maximise stability (Mhyr and von Wendt 1990; Healey et al 1997; Ham et al 1998) with McDonald et al (2004) suggesting that the provision of adaptive equipment to children with cerebral palsy should be individualised based on functional and contextual factors. Disparity in the literature exists regarding the optimal sitting position for a child with cerebral palsy. Some authors advocate the upright posture (Nwaobi et al 1983; Nwaobi 1986, 1987; Green and Nelham 1991). Others are in favour of straddled (Reid 1996) and forward inclined seating (Myhr and von Wendt 1990, 1991; Miedaner 1990; Myhr et al 1995; van der Heide 2003) and there are those that advocate a reclined posture (McClenaghan et al 1992; Hadders et al 1999) to enhance postural control. It is recognised that some of these studies do not refer to cerebral palsy as a heterogeneous group. Please refer to previous sections reviewing these studies.
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Congenital Hip Deformity / Developmental Dysplasia Developmental dysplasia is a condition of pathological hip instability characterised by dislocation or subluxation of the femoral head from the acetabulum (Lowes and Orlin 2005) with incidence being reported at 2:1000 live births (Cox and Kernohan 1998). Rodgers et al (1998) attributes the cause of developmental dysplasia to both environmental (birth complications) and genetic factors. Ham et al (1998) support this assumption stating that developmental dysplasia may be due to hormonal joint laxity, genetically determined joint laxity and delivery in the breech position. Limited hip abduction and asymmetry are manifestations of this condition, with typical neonates displaying 75° and 90° abduction in each hip (Lowes and Orlin 2005). This condition is also characterised by poor hip socket development, poor weight bearing surface and leg length discrepancy if the femur is subluxed from the acetabulum (Lowes and Orlin 2005). Early diagnosis is imperative as this condition is treatable in the early stage, however long term permanent damage will incur if left untreated of if late diagnosis occurs (Cox and Kernohan 1998, Rodgers et al 1998, Lowes and Orlin 2005). Treatment usually comprises of orthopaedic surgery and splinting (Cox 1995). Positioning problems include reduced abduction and flexion at the hip joint, leg length discrepancy, (Lowes and Orin 2005) and if not corrected early, delayed walking and abnormal gait patterns will be evident (Ham et al 1998). Two studies identified discuss the seating and mobility issues encountered by children with developmental dysplasia. Cox (1995) used a survey method with parents of 11 children who either had undergone or were undergoing treatment for late diagnosed developmental dysplasia. Results highlighted that there was insufficient equipment able to accommodate children in plaster and splints and there was a need to develop seating products, with emphasis placed on mobility. Small sample size and a response rate of 48% limit the generalisability of these findings. Cox et al (1998) further researched seating and mobility in a subsequent study, again utilising a survey method. To identify problems, a survey of 113 affected families in England and Northern Ireland was conducted. Results identified problems in areas of mobility, which creates emotional and social difficulties in family routines. Regarding mobility, it was found that due to the child’s loss of mobility, parents resorted to lifting and carrying the child more frequently, which became problematic as the child increased in age and size. Seating equipment in the home often had to be adapted and improvised to accommodate the size of the splint, therefore compromising safety. Lack of mobility and seating problems were found to restrict the child’s movement and restricted parental activity. The authors (Cox et al 1998) suggest problems could be improved in this population by provision of special devices that would allow mobility in the car, in a pushchair and provide seating in the home environment. Caution must be applied when generalising results as finding are based on a 38% response rate.
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Rett Syndrome Rett Syndrome is a rare neurodevelopmental disorder which predominantly affects females (Cass et al 2003). It is characterised by progressive loss of intellectual functioning, loss of fine and gross motor skills, loss of purposeful hand movements and development of stereotypical hand movements such as hand wringing, washing and clapping (Parker 2000; Reed 2001), difficulty or inability ambulating (Parker 2000) and marked changes in emotional development and behaviour (Ham et al 1998). Research has evidenced the prevalence of fractures as 20.9% amongst this population (McDonald et al 2002). Rett syndrome is also classified as a pervasive developmental disorder as it also characterised by severe and complex impaired social interaction, communication and behaviour (Rodgers et al 1998) According to Parker (2000) normal development occurs between the first 6-18 months of life, after which regression appears to occur. Clinical manifestations also include muscle atrophy, increased spasticity and seizures (Ham et al 1998), hypotonia, ataxia, and trunk rocking (Effgen 2005). Scoliosis is the primary orthopaedic complication of Rett syndrome with onset associated with stereotypical arm and hand movements, slowing down of righting and equilibrium reactions, age (McClure et al 1998) alterations in muscle tone, spasticity, and muscle incoordination (Harrison and Webb 1990). Research has evidenced that there is a significant relationship between the prevalence of Rett syndrome scoliosis and orthopaedic risk factors. McClure et al (1998) concluded that rett scoliosis may be due orthopaedic asymmetries rather than a neurological form of scoliosis, with age, abnormal upper body positioning, and non-ambulation as significant predictors of scoliosis. Cass et al (2003) also suggest that early asymmetry of the pelvis as well as shoulder protraction and elevation may be a precursor to fixed deformity. Clinical implications therefore would be to promote bilateral symmetrical muscular balance through proper sitting and lying positions (McClure et al 1998). Ham et al (1998) suggest that in the early stages, weight bearing should be encouraged to help minimise and delay the onset of deformity, as well as the use of spinal jackets. Ham et al (1998) also suggest that soft moulded seats with supports at the backrest are recommended.
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Duchenne Muscular Dystrophy Duchenne Muscular Dystrophy (DMD) is a genetic disorder characterised by progressive proximal muscle weakness (Reed 2001). This disorder only affects boys, with few surviving beyond 20-30 years old and mortality as a consequence of cardiopulmonary compromise (Ham et al 1998). In DMD, muscles break down and are replaced with fat and scar tissue, (pseudo hypertrophy) resulting in the muscles appearing bulky, with the calf muscles looking unusually large (Parker 2000). Impairment of muscle is affected proximally to distally ( Lowes and Orlin 2005) with Rodgers at al (1998) suggesting involvement begins in the proximal musculature of the pelvis, proceeding to the shoulder girdle and subsequently to the distal muscle groups. Thompson et al (1998) add that muscle involvement is bilateral and symmetrical. To compensate for muscle weakness, the child may resort to using the upper extremities to assist knee extension by using his hands to ‘walk up’ from floor to standing (Gower’s sign) (Ham et al 1998; Lowes and Orlin 2005). In addition hyperextension or lordosis of the lumbar spine may be apparent as a compensatory posture in order to maintain an upright position and head in midline (Ham et al 1998). Early signs of DMD are evident when the child displays increased plantar flexion by walking on their toes at approximately 1 year old (Parker 2000). Brown (2002) suggests that loss of ambulation may occur between 8-11 years, with Lord et al (1990) reporting wheelchair dependence at 6-15 years. As muscle weakness progresses, flexion contractures (Reed 2001) and scoliosis (Lowes and Orlin 2005) will occur. Research highlights that pain is related to spinal deformity (Lui et al 2003). Brown (2002) highlights that pelvic obliquity will coincide with scoliosis resulting in difficulty in sitting due to unequal weight distribution over the ischial tuberosities. Bakker et al (2000) suggest that correct positioning and stretching may delay the development of contractures and spinal deformity. Parker (2000) also highlights good body alignment is imperative especially with older children for efficient respiratory function as many may be reliant on ventilators to assist breathing. Due to the progression of DMD, the child’s postural needs will continually change; hence seating interventions must be able to accommodate change. Intervention may also be complex as proximal stabilisation is one of the first functions to diminish in DMD, therefore external stabilisation with adaptive seating is required (Clark et al 2004). Intervention involves the use of knee-ankle-foot orthoses (Ham et al 1998; Thompson et al 1998; Rodger et al 1998; Lowes and Orlin 2005) however a recent systematic review suggested that although the use of knee ankle foot othoses can prolong assisted walking and standing, it is uncertain whether they can prolong functional walking (Bakker et al 2000). Ham et al (1998) also highlight that the success of seating systems is variable as it cannot prevent the onset of scoliosis in this population. Initially a light-weight self-propelling chair may be required, progressing onto a powered wheelchair. Clark et al (2004) suggest common clinical practice regarding seating is to level the pelvis, with a firm seat base, align the trunk with lateral supports to facilitate head alignment and support the elbows and forearms on a tray or with arm supports. Ham et al (1998) highlight that reclining or tilting the seating system may reduce the load on the spine, however may be contraindicated by the child adopting an exaggerated lordosed position of the lumbar spine to maintain upright balance and the head in midline. According to Clark et al (2004) limited research exists regarding
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the effects of postural support in seating on health and function of young people with neuromuscular disorders. Clark et al (2004) conducted a prospective two-period randomised crossover study to measure the effects of postural support in seating on posture, respiration and upper limb function for young people with neuromuscular disorders. Nineteen participants aged 6-22 years old, with a diagnosis of DMD (n=15) or Freidreich’s Ataxia (n=4) were assessed in wheelchair seating and in adaptive seating via a standard protocol. Sitting posture, respiration and upper limb function was compared when sitting in a standard wheelchair and in adaptive seating. Results concluded that there were no significant differences in respiratory function and no overall improvement in upper limb function when compared in the two seating systems, however suggested that adaptive seating can improve the posture of this client group by changing body alignment of young people in the chair. Small sample size and difficulty with accurate postural measurements in the clinical setting limit the generalisability of these findings. The proposed protocol used in the study has not yet been tested for reliability and validity. Spina Bifida Spina bifida, is described as a congenital defect of the vertebral arches in the spinal column (Rodgers et al 1998) whereby the neural tube fails to unite therefore exposing a gap over which the skin is defective (Ham et al 1998). Parker (2000) highlights three spina bifida classifications and includes spina bifida occulta (minor defect not obvious at the skin surface), meningocele (protruding sac containing meninges) and myelomeningocele (protruding sac containing meninges and spinal cord). It is suggested that the cause of spina bifida results from genetic and environmental factors (Reed 2001; Rodgers et al 1998). Numerous clinical manifestations are apparent with spina bifida and include the following: fine motor and hand skill delay (Reed 2001), hydrocephalus (Pountney and McCarthy 1998), impaired or loss of sensation, paralysis, vasomotor dysfunction (Westcott and Goulet 2005), perceptual dysfunction (visual, auditory, propriceptive, tactile , kinaesthetic and hypo- or hyperresponsitivity), learning disability (Reed 2001), pressure sores (Vaisbuch 2000) and psychosocial problems (Pountney and McCarthy 1998). Evidence also suggests that children with spina bifida frequently report clinically significant yet under recognised and untreated pain (Clancy et al 2005). Neurological dysfunction will also contribute to the onset of orthopaedic problems posing problems for seating and positioning, with the level of the lesion determining functional ability. Spinal deformities associated with spina bifida include scoliosis, kyphosis or kyphoscoliosis (Reed 2001), with deformity being present at birth or occurring as the child develops (Pountney and McCarthy 1998). Retention of primitive reflexes, abnormal muscle tone, limited range of movement in the extremities, poor postural control of trunk, poor coordination and presence of hip
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dislocation / subluxation (Reed 2001) and flexion contractures of knees and ankle (Pountney and McCarthy 1998) are factors which must be considered regarding seating intervention. Ham et al (1998) suggest that seating objectives with this population are to provide a stable base of support, maintain alignment of the spine, relieve discomfort over pressure areas, encourage cardiopulmonary function and improve independence.
One study identified investigated the effect on interface pressure distribution in a group of children with complete paraplegia due to myelomeningocele and a group of aged matched controls in different sitting positions (Vaisbuch et al 2000). This study concluded that the lean forward position (hips flexed to 45°) produced the largest reduction in interface pressure, however the authors acknowledge the children felt apprehensive in this posture. The tilt position also reduced interface pressure, with the authors suggesting that tilting is used to relieve pressure during periods of non functional activity. No other studies were identified regarding seating principles with this population.
Conclusion Following a review of the literature, it is concluded that positioning principles are based on empirical and evidence and expert opinion regarding children and young people with neuromotor and neuromuscular disabilities. The majority of research conducted reflects the impact of seating and positioning with the cerebral palsy population. Continued disparity in the literature, small sample sizes and short periods of data collection limit the generalisability of the findings, although are important in terms of clinical significance. Limited research exists regarding children with neuromuscular conditions. It is recognised that appropriate positioning in children with physical disabilities is important to facilitate engagement in functional activity and enable participation with the environment (Jones and Gray 2005). Research has evidenced that proper positioning can improve upper extremity function (Mhyr and von Wendt 1991, Mhyr et al 1995), postural alignment (Washington et al 2002), and prevent the development of deformity (Pountney et al 2002). Children and young people who lack postural control and are unable to maintain appropriate postures therefore will require external support from seating systems. The goal of intervention hence is to provide adaptive seating to create a functional seated position to maintain health and function as part of a postural management approach.
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References Bakker JPJ, de Groot IJM, Beckerman H, de Jong BA & Lankhorst GJ (2000) The effects of knee-ankle-foot orthoses in the treatment of duchenne muscular dystrophy: review of the literature. Clinical Rehabilitation, 14, 343-359. Brogren E, Hadders-Algra M & Foressberg H (1998) Postural control in sitting children with cerebral palsy. Neuroscience and Behavioural Reviews, 22, 591-596. Brown G (2002) Muscular dystrophy. In A Turner, M Foster & E Johnson E (Ed). Occupational Therapy and Physical Dysfunction, Principles, Skills and Practice. London: Churchill Livingstone. Case-Smith J, Fisher AG & Bauer D (1989) An analysis of the relationship between proximal and distal control. American Journal of Occupational Therapy, 43, 657-662. Cass H, Reilly S, Owen L, Wisbeach A, Weekes L, Slonims V, Wigram T & Charman (2003) Findings from a multidisciplinary clinical case series of females with rett syndrome. Developmental Medicine and Child Neurology, 45, 325-337. Clancy CA, McGrath PJ, Oddson BE (2005) Pain in children and adolescents with spina bifida. Developmental Medicine and Child Neurology, 47, 27-34. Clark J, Michael S & Morrow M (2004) Wheelchair postural support for young people with progressive neuromuscular disorders. International Journal of Therapy and Rehabilitation, 11, 365-371. Cooper D, Dilabio RT, Broughton G & Brown D (2001) Dynamic seating components for the reduction of spastic activity and enhancement of function. Seventeenth International Seating Symposium, February 22-24. Cornell MS (1995) The hip in cerebral palsy. Developmental Medicine and Child Neurology, 37, 3-18. Cox SL & Kernohan WG (1998) They cannot sit properly or move around: seating and mobility during the treatment for developmental dysplasia of the hip in children. Pediatric Rehabilitation, 2, 129-134. Cox SL (1995) Problems of seating and mobility encountered by children with developmental dysplasia of the hip. Clinical Rehabilitation, 9, 190-197. Engström B (2002) Ergonomic Seating A True Challenge Wheelchair Seating and Mobility Principles. Sweden: Posturalis Books. Erdhardt RP, Merril SC (1998) Neurological dysfunction in children. In ME Neistadt, EB Crepeau (Ed) Willard and Spackman’s Occupational Therapy. London: Lippincott Williams & Wilkins.
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Nwaobi OM (1986) Effects of body orientation in space on tonic muscle activity of patients with cerebral palsy. Developmental Medicine and Child Neurology, 28, 41-44. Nwaobi OM, Brubacker CE, Cusick B & Sussman MD (1983) Electromyographic investigation of extensor activity in cerebral-palsied children in different seating positions. Developmental Medicine and Child Neurology, 25, 175-183. Nwaobi OM (1987) Sitting orientations and upper extremity function in children with cerebral palsy. Physical Therapy, 67, 1209-1213. Pain H, McLellan L & Gore S (2003) Choosing Assistive Devices A Guide For Users and Professionals. London: Jessica Kinsley Publishers. Parker GE (2000) Other common pediatric disorders. In JW Solomon (Ed) Pediatric Skills for Occupational Therapy Assistants. London: Mosby. Pope PM (2002) Posture management and special seating. In Edwards S (Ed) Neurological Physiotherapy. London: Churchill Livingstone. Pountney TE, Mandy A, Green E & Gard P (2002) Management of hip dislocation with postural management. Child: Care, Health and Development, 28, 179-185. Pountney TE & McCarthy (1998) Neural tube defects: spina bifida and hydrocephalus. In M Stokes (Ed) Neurological Physiotherapy. London: Mosby. Pountney TE, Mulcahy CM, Clarke SM, Green EM (2001) The Chailey Approach to Postural Management. Active Design. Pynt J, Higgs J & Mackey M (2001) Seeking the optimal posture of the seated lumbar spine. Physiotherapy Theory and Practice, 17, 5-21. Reed KL (2001) A Quick Reference to Occupational Therapy. USA: Aspen Publishers Reese ME, Msall ME & D’Amanto C (1990) The influence of asymmetric primitive reflexes and tone on orthopedic deformity of children with cerebral palsy. (abstract) Developmental Medicine and Child Neurology, 32, 43. Reid DT (1996) The effects of the saddle seat on seated postural control and upper extremity movement in children with cerebral palsy. Developmental Medicine and Child Neurology, 38, 805-815. Reid DT & Rigby P (1996) Development of improved anterior pelvic stabilisation devices for children with cerebral palsy. Physical and Occupational Therapy in Pediatrics, 16, 91-96. Reid DT, Sochaniwskyj A & Milner M (1991) An investigation of postural sway in sitting of normal children and children with neurological disorders. Physical and Occupational Therapy in Pediatrics, 11, 19-35.
33
Reid DT (1995) Development and preliminary validation of an instrument to assess quality of sitting of children with neuromotor dysfunction. Physical and Occupational Therapy in Pediatrics, 15, 53-81. Reid DT & Sochaniwsky A (1991) Effects of anterior-tipped seating on respiratory function of normal children and children with cerebral palsy. International Journal of Rehabilitation Research, 14, 203-212. Rigby P, Reid D, Schoger S, & Ryan S (2001) Effects of a wheelchair mounted rigid pelvic stabiliser on care giver assistance for children with cerebral palsy. Assistive Technology, 13, 2-11. Rodgers SL, Gordon CT, Schazenbacher KE & Case-Smith (2001) Common diagnosis in pediatric occupational therapy practice. In J Case-Smith (Ed) Occupational Therapy for Children. London: Mosby. Scoliosis Research Society (2002) Retrieved from: http://www.srs [accessed 5th July 2005]. Scrutton D, Baird G, & Smeeton N (2001) Hip dysplasia in bilateral cerebral palsy and natural history in children aged 18 months to 5 years. Developmental Medicine and Child Neurology, 43, 586-600. Shimizu ME, Tanaka S, Takamagari H, Honda K, Shimizu H & Nakamura S (1994) Optimal positioning for an adult athetoid cerebral palsy patient in a wheelchair. Hiroshoma Journal of Medical Science, 43, 69-72. Shoham Y, Meyer S, Katz-Leurer M & Weiss PLT (2004) The influence of seat adjustment and a thoraco-lmbar-sacral orthosis on the distribution of body seat pressure in children with scoliosis and pelvic obliquity. Disability and Rehabilitation, 26, 21-26. Thompson N, Fahal I & Edwards RHT (1998 ) Muscle disorders in childhood. In M Stokes (Ed) Neurological Physiotherapy. London: Mosby. Trefler E & Taylor SJ (1991) Prescription and positioning: evaluating the physically disabled individual for wheelchair seating. Prosthetics and Orthotics International, 15, 217-224. Turner C (2001) Posture and seating for wheelchair users: an introduction. British Journal of Therapy and Rehabilitation, 8, 24-28. Tyldesley B & Grieve J (2002) Muscles, Nerves & Movement in Human Occupation. Oxford: Blackwell Science. Van der Heide JC, Otten B, van Eykern LA, Hadders-Algra M (2003) Development of postural adjustments during reaching in sitting children. Exp Brain Research, 151, 32-45.
34
Vaisbuch N, Meyer S, Weiss PL (2000) Effect of seated posture on interface pressure in children who are able bodied and who have myelomeningocele. Disability and Rehabilitation, 22, 749-755. Washington K, Deitz JC, White OR & Scwartz IS (2002) The effects of a contoured foam seat on postural alignment and upper-extremity function in infants with neuromotor impairment. Physical Therapy, 82, 1064-1076. Wandel JA (2000) Positioning and handling. In JW Solomon (Ed) Pediatric Skills for Occupational Therapy Assistants. London: Mosby. Wandel JA (2000) Cerebral palsy. In JW Solomon (Ed) Pediatric Skills for Occupational Therapy Assistants. London: Mosby. Westcott SL & Goulet CG (2005) Neuromuscular system: structures, functions, diagnosis, and evaluation. In SK Effgen (Ed) Meeting the Physical Therapy Needs of Children. Philadelphia: FA Davis Company. Wright-Ott C, Egilson S (2001) In J Case-Smith (Ed) Occupational Therapy for Children. London: Mosby. Yang TC, Chan RC, Wong TT, Bair WN, Kao CC, Chuang TY & Hsu TC (1996) Quantitative measurement of improvement in sitting balance in children with spastic cerebral palsy after selective rhizotomy. American Journal of Physical Medicine and Rehabilitation, 75, 348-352. Young NL, Wright JG, Lam TP, Rajaratnam K, Stephens D & Wedge JH (1998) Windswept hip deformity in spastic quadriplegic cerebral palsy. Pediatric Physical Therapy, 10, 94-100.
35
APPENDIX 1 The following tables indicate data bases searched and key words utilized regarding specific themes. TABLE 1: Seating Data Base Key Words CINAHL exp seating/ AND Child exp equipment design AND child exp seating/ AND child dynamic seating BIDS seating Pubmed seating seating principles seating and positioning Proquest adaptive seating seating seat$ AND children AND position Embase exp seat/ AND child dynamic seating AMED exp seating/ AND child exp equipment design/ AND exp seating
AND child dynamic seating Medline (Ovid) dynamic seating seating and positioning OTDbase seating ASSIA positioning and seating Psychinfo seating British Nursing Index seating Seat$ Zetoc seating pe*diatric seating
36
ISI Web of Science seating TABLE 2: Positioning / Posture Data Base Key Words CINAHL patient positioning BIDS posture positioning Pubmed seating and posture Proquest seating and positioning Embase positioning AMED exp positioning/ patient positioning AND exp pelvis/ Medline (Ovid) seating and positioning OTDbase positioning ASSIA seating and positioning Psychinfo positioning British Nursing Index patient positioning Zetoc seating and positioning ISI Web of Science seating and positioning seating and posture positioning and posture
37
TABLE 3: Cerebral Palsy Data Base Key Words CINAHL exp cerebral palsy/ AND posture/ AND
child BIDS cerebral palsy Pubmed cerebral palsy and seating Proquest cerebral palsy and positioning cerebral palsy and seating spastic cerebral palsy and posture spastic cerebral palsy and position Embase exp cerebral palsy/ AND child exp cerebral palsy/ AND posture/ AND
child AMED exp cerebral palsy/ AND seating Medline (Ovid) cerebral palsy and seating OTDbase cerebral palsy ASSIA cerebral palsy and positioning cerebral palsy and posture Psychinfo cerebral palsy and posture British Nursing Index Exp cerebral palsy/ AND seating Zetoc cerebral palsy and seating ISI Web of Science Cerebral palsy cerebral palsy and positioning cerebral palsy and posture
38
TABLE 4: Duchenne Muscular Dystrophy Data Base Key Words CINAHL exp duchenne muscular dystrophy/ AND
child BIDS muscular dystrophy Pubmed duchenne muscular dystrophy and seating duchenne muscular dystrophy and
posture Proquest exp duchenne muscular dystrophy/ AND
exp child/ Embase duchenne muscular dystrophy/ AND exp
child/ AMED duchenne muscular dystrophy Medline (Ovid) duchenne muscular dystrophy and seating OTDbase duchenne muscular dystrophy ASSIA duchenne muscular dystrophy duchenne muscular dystrophy AND
posture Psychinfo duchenne muscular dystrophy British Nursing Index duchenne muscular dystrophy Zetoc duchenne muscular dystrophy and seating duchenne muscular dystrophy and child duchenne muscular dystrophy and
posture ISI Web of Science Duchenne muscular dystrophy
39
TABLE 5: Congenital Hip Deformity / Developmental Dysplasia Data Base Key Words CINAHL exp hip deformity congenital/ AND child BIDS congenital hip deformity developmental dysplasia Pubmed congenital hip deformity and seating congenital hip deformity and posture Proquest developmental dysplasia Embase exp hip dislocation congenital/ Medline (Ovid) Congenital hip deformity AND child
AND hip dislocation AMED exp hip dislocation congenital/ OTDbase developmental dysplasia ASSIA developmental dysplasia Psychinfo developmental dysplasia British Nursing Index exp congenital abnormality/ AND exp
developmental dysplasia/ Zetoc congenital hip developmental dysplasia developmental dysplasia and seating developmental dysplasia and child ISI Web of Science developmental dysplasia
40
TABLE 6: Rett Syndrome Data Base Key Words CINAHL rett syndrome BIDS rett syndrome Pubmed rett syndrome and posture Proquest rett syndrome and posture Embase exp rett syndrome/ AND exp child AMED exp rett syndrome/ AND exp child Medline (Ovid) rett syndrome and child rett syndrome and posture rett syndrome and posture rett syndrome and child development OTDbase rett syndrome ASSIA rett syndrome Psychinfo rett syndrome British Nursing Index rett syndrome Zetoc rett syndrome ISI Web of Science rett syndrome
41
TABLE 7: Spina Bifida Data Base Key Words CINHAL spina bifida and seating spina bifida and positioning BIDS spina bifida Pubmed spina bifida and seating spina bifida and posture Proquest spina bifida and seating AMED exp child/ AND exp abnormalities/ AND
exp spina bifida/ exp child/ AND exp meningomyelocele Medline (Ovid) spina bifida and posture spina bifida and children OTDbase spina bifida ASSIA spina bifida and posture and seating Psychinfo spina bifida and children British Nursing Index spina bifida and seating Zetoc spina bifida and seating spina bifida and posture spina bifida ISI Web of Science spina bifida and child spina bifida and posture spina bifida and seating
Res
ults
and
Con
clus
ions
Res
ults
sugg
est i
n no
rmal
ch
ildre
n, th
ere
is a
sign
ifica
nt
but w
eak
corr
elat
ion
be
twee
n pr
oxim
al c
ontro
l and
th
e de
velo
pmen
t of d
ista
l sk
ill, s
ugge
stin
g th
at
[pro
xim
al-d
ista
l prin
cipl
e m
ay n
ot b
e an
app
ropr
iate
po
stul
ate
on w
hich
to b
ase
treat
men
t / in
terv
entio
n.
Sign
ifica
nt re
latio
nshi
p to
su
ppor
t a fu
nctio
nal
rela
tions
hip
betw
een
prox
imal
and
dis
tal m
otor
fu
nctio
ns.
Prev
ious
ly re
porte
d tre
nds i
n pr
esen
tatio
n co
nfirm
ed:
↑ po
or g
row
th, f
ixed
de
form
ity a
nd sc
olio
sis i
n ad
ulth
ood.
↑
mob
ility
in a
dole
scen
ce,
follw
ed b
y de
clin
e in
ad
ulth
ood.
H
igh
depe
nden
cy le
vel.
Li
mite
d co
gniti
on/c
omm
unic
atio
n sk
ills.
Sl
ight
impr
ovem
ent i
n A
NS
func
tion
in a
dulth
ood.
Fe
edin
g di
ffic
ultie
s ↑
into
m
iddl
e ch
ildho
od, r
each
inf a
pl
atea
u.
Find
ings
con
firm
th
at R
ett S
yndr
ome
is n
ot
dege
nera
tive
and
sugg
ests
th
at in
terv
entio
n a
nd su
ppor
t to
mai
ntai
n an
d in
crea
se
mot
or sk
ills,
daily
livi
ng
skill
s and
cog
nitiv
e an
d co
mm
unic
atio
n is
ap
prop
riate
.
Met
hodo
logy
Post
ure
and
fine
mot
or c
ontro
l w
ere
mea
sure
d by
the
PFM
AI,
with
test
ing
cond
ucte
d by
J C
ase-
Smith
and
4 u
nder
grad
uate
st
uden
ts tr
aine
d in
PFM
AI
adm
inis
tratio
n. P
ostu
re o
bser
ved
by th
e in
fant
s abi
lity
to
inde
pend
ently
sust
ain
mov
emen
t ag
ains
t gra
vity
whe
n in
pro
ne
and
supi
ne. (
post
ural
reac
tions
en
cour
aged
by
attra
ctin
g in
fant
s at
tent
ion
to d
evel
opm
enta
lly
appr
opria
te to
ys.
Fine
mot
or
skill
s ass
esse
d by
elic
iting
va
rious
gra
spin
g an
d ha
nd
posi
tions
by
pres
entin
g ch
ildre
n w
ith 3
obj
ects
. In
fant
s pos
ition
ed
in se
mi r
eclin
e. F
our m
inut
es
of te
stin
g al
loca
ted
for r
each
and
m
anip
ulat
ion
of e
ach
obje
ct
All
parti
cipa
nts s
een
in
mul
tidis
cipl
inar
y te
rtiar
y he
alth
cl
inic
(pae
diat
ricia
n, P
T, S
LT.
OT
and
mus
ic th
erap
ist).
A
sses
smen
t are
as in
clud
ed:
oral
mot
or sk
ills,
feed
ing
prob
lem
s, gr
owth
, bre
athi
ng
prob
lem
s , p
ostu
ral
abno
rmal
ities
and
join
t de
form
ities
, epi
leps
y,
ster
eoty
pies
and
han
d m
ovem
ents
, sel
f-ca
re, a
nd
cogn
itive
and
com
mun
icat
ion
skill
s. A
reas
ass
esse
d by
pa
rent
al/c
arer
repo
rts, d
irect
ob
serv
atio
n, m
ultid
isci
plin
ary
exam
inat
ion,
clin
ical
repo
rts,
vide
o ta
ped
asse
ssm
ent s
essi
ons
and
asse
ssm
ent t
ools
e.g
. Sc
hedu
le fo
r O
ral M
otor
A
sses
smen
t.
Parti
cipa
nts
60 n
orm
al in
fant
s (2-
6 m
onth
s:
mea
n 4.
4 m
onth
s) fr
om d
ay c
are
faci
lity
test
ed a
s mea
sure
d by
th
e PF
MA
I. 87
par
ticip
ants
( 2y
eras
1 m
onth
–
44 y
ears
10
mon
ths)
with
a
conf
irmed
dia
gnos
is o
f ret
t sy
ndro
me
seen
bet
wee
n 19
93
and
2000
.
n= 7
6 (c
lass
ic re
tt sy
ndro
me)
n=
11 (a
typi
cal p
rese
ntat
ion
of
diso
rder
)
Stud
y D
esig
n
Cas
-ser
ies d
esig
n
Cas
e-Se
ries d
esig
n
Purp
ose
To in
vest
igat
e th
e re
latio
nshi
p be
twee
n pr
oxim
al a
nd d
ista
l mot
or
cont
rol u
sing
the
Pos
tura
l Fi
ne M
otor
Ass
essm
ent S
cale
fo
r Inf
ants
(PFM
AI)
To g
athe
r sys
tem
atic
dat
a fr
om a
mul
tidis
cipl
inar
y cl
inic
al a
sses
smen
t cas
e lo
ad
of fe
mal
es w
ith re
tt sy
ndro
me,
to a
llow
clin
ical
m
anife
stat
ions
of t
he d
isor
der
to b
e st
atis
tical
ly v
alid
ated
in
orde
r to
disc
uss i
mpl
icat
ions
re
gard
ing
man
agem
ent o
f the
co
nditi
on a
nd d
irect
ions
for
futu
re re
sear
ch.
Aut
hor /
Dat
e / T
itle
Cas
e-Sm
ith J,
Fis
her A
G &
Bau
er
D (1
989)
. A
n A
naly
sis o
f the
Rel
atio
nshi
p be
twee
n Pr
oxim
al a
nd D
ista
l Mot
or
Con
trol.
Cas
s H, R
eilly
, Ow
en L
, Wis
beac
h A
, Wee
kes L
, Wig
ram
T &
C
harm
an T
(200
3).
Find
ings
from
a m
ultid
isci
plin
ary
clin
ical
cas
e se
ries o
f fem
ales
with
re
tt sy
ndro
me.
1
Res
ults
and
Con
clus
ions
56%
repo
rted
expe
rienc
ing
pain
onc
e a
wee
k or
mor
e of
ten;
Pai
n oc
curr
ed m
ore
freq
uent
ly in
the
head
, nec
k,
back
, abd
omen
, sho
ulde
rs,
legs
and
han
ds.
43∕4
9 w
ith h
ydro
ceph
alus
re
porte
d he
adac
hes.
15
∕19
with
out h
ydro
ceha
lus
repo
rted
head
ache
s..
Chi
ldre
n re
porti
ng in
tens
e pa
in, a
lso
repo
rt ↑
freq
uenc
y an
d ↑
pain
loca
tions
. Pa
rent
a m
ost r
elia
ble
st
repo
rting
loca
lity
of
child
ren’
s pai
n.
Find
ings
con
clud
e ch
ildre
n w
ith so
ina
bifid
a re
port
clin
ical
ly si
gnifi
cant
, un
der
reco
gnis
ed &
unt
reat
ed p
ain.
Res
ults
sugg
est t
here
is a
de
ficie
ncy
in e
quip
men
t av
aila
ble
to c
ope
with
and
m
anag
e ch
ildre
n in
pla
ster
, in
clud
ing
prod
ucts
to h
elp
in
seat
ing.
Spe
cial
em
phai
s is
plac
ed o
n m
obili
ty.
This
pilo
t stu
dy c
onfir
med
ne
ed fo
r fut
ure
focu
sed
rese
arch
to p
rovi
de p
rodu
cts
sugg
este
d.
Met
hodo
logy
Dat
a co
llect
ed v
ia p
aren
tal
repo
rt qu
estio
nnai
res (
The
Pedi
atric
Pai
n Q
uest
ionn
aire
) an
d ch
ild re
port
ques
tionn
aire
(V
isua
l Ana
logu
e Sc
ale)
and
, fr
om t
med
ical
reco
rds
to
inve
stig
ate
ain
inte
nsity
, lo
catio
n, fr
eque
ncy
and
dura
tion.
M
easu
res a
dmin
istra
ted
by o
ne
of tw
o tra
ined
Mas
ters
leve
l vo
lunt
eer i
n se
para
te a
rea
from
cl
inic
to e
nsur
e in
depe
nden
t ra
ting.
24 q
uest
ionn
aire
s dis
tribu
ted,
of
whi
ch 1
1 w
ere
retu
rned
(48.
8%
resp
onse
rate
). Q
uest
ionn
aire
s eith
er d
istri
bute
d by
pos
t or t
hrou
gh p
aren
tal
supp
ort g
roup
s and
wer
e co
mpl
eted
by
pare
nts.
Parti
cipa
nts
n= 6
8 ch
ildre
n w
ith sp
ina
bifid
a
(30
mal
es, 3
8 fe
mal
es)
Mea
n ag
e 12
yea
rs 8
mon
ths
(ran
ge 8
-19
year
s).
n=59
(mye
lom
enin
goce
le)
n= 6
lipo
mye
lom
enin
goce
le
n= 3
lipo
men
ingo
cele
. n=
49
shun
ted
hydr
ocep
halu
s n=
26 a
mbu
late
d fu
ll tim
e C
hild
ren
able
to c
omm
unic
ate
in
Engl
ish
and
had
no si
gnifi
cant
co
gniti
ve li
mita
tions
. R
ecru
ited
from
regi
onal
ch
ildre
n’s c
entre
. Pa
rent
s (m
ean
age
43 y
ears
4
mon
ths)
Fo
r com
paris
on p
urpo
ses
sam
ple
divi
ded
into
2 g
roup
s
Pare
nts
of 1
1 ch
ildre
n (2
boy
s;
9 gi
rls)
who
wer
e ei
ther
un
derg
oing
or h
ad u
nder
gone
tre
atm
ent f
or la
te d
iagn
osed
D
DH
, wer
e su
rvey
ed b
y qu
estio
nnai
re.
Stud
y D
esig
n
Pros
pect
ive
stud
y.
Que
stio
nnai
re (p
ilot s
tudy
) (s
emi s
truct
ured
and
ope
n)
3 qu
estio
nnai
res s
ent t
o pa
tient
s in
Nor
ther
n Ir
elan
d; 2
in th
e re
publ
ic o
f Ire
land
; and
6 in
En
galn
d.
Que
stio
ns g
ener
ated
from
an
alys
is o
f the
lite
ratu
re a
nd
info
rmat
ion
obta
ined
from
de
taile
d se
mi-
stru
ctur
ed
inte
rvie
ws w
ith su
rgeo
ns a
nd
staf
f inv
olve
d in
trea
tmen
t.
Que
stio
nnai
re fo
cuse
s on
seat
ing
and
mob
ility
pro
blem
s.
Purp
ose
1) T
o in
vest
igat
e th
e na
ture
an
d pr
eval
ence
of p
ain
in
child
ren
and
adol
esce
nts w
ith
spin
a bi
fida.
2)
To
com
pare
chi
ldre
n’s a
nd
pare
nts’
pae
diat
ric p
ain
ratin
gs to
det
erm
ine
whe
ther
or
not
con
cord
ance
exi
sts
betw
een
the
two.
To
con
firm
the
clin
ical
su
spic
ion
that
sign
ifica
nt
prob
lem
s are
enc
ount
ered
by
child
ren
and
thei
r car
e-gi
vers
in
cop
ing
the
treat
men
t of
splin
ting
resu
lting
from
late
di
agno
ses d
evel
opm
enta
l dy
spla
sia
of th
e hi
p (D
DH
).
Aut
hor /
Dat
e / T
itle
Cla
ncy
CA
, McG
rath
PJ &
Odd
son
BE
(200
5).
Pain
in a
dole
scen
ts w
ith sp
ina
bifid
a.
Cox
SL
& M
olla
n R
AB
(199
5)
Prob
lem
s of s
eatin
g an
d m
obili
ty
enco
unte
red
by c
hild
ren
with
de
velo
pmen
tal d
yspl
asia
of t
he h
ip.
2
Res
ults
and
Con
clus
ions
Res
lults
sugg
este
d th
at
pare
nts i
denf
ied
soci
al,
emot
iona
l and
phy
sica
l pr
oble
ms.
Pro
blem
s inc
lude
d si
ze a
nd sh
ape
of sp
lint,
trans
porti
ng a
ns se
atin
g pr
oble
ms a
nd d
isru
ptio
n of
fa
mily
rout
ines
. Su
ch p
robl
ems m
ay b
e al
levi
ated
by
prov
isio
n of
sp
ecia
lised
dev
ices
that
w
ould
per
mit
mob
ility
by
car,
in a
pus
hcha
ir an
d pr
ovid
e se
atin
g in
the
hom
e.
5 de
velo
ped
spas
tic
hem
iple
gia
1dev
elop
ed sp
astic
te
trapl
egia
1
deve
lope
d sp
astic
te
trapl
egia
with
ath
etos
is.
Res
ults
sugg
est b
asic
or
ient
atio
n of
pos
tura
l ad
just
men
ts o
f chi
ldre
n de
velo
ping
spas
tic C
P w
as
inta
ct, w
ith m
ain
prob
lem
s be
ing
↓ ab
ility
to m
odul
ate
post
ural
adj
ustm
ent t
o ta
sk
spec
ific
cons
train
ts.
The
child
with
spas
tic a
thet
osis
sh
owed
dis
tinct
abn
orm
aliti
es
in b
asic
org
anis
atio
n of
po
stur
al a
djus
tmen
ts.
Rea
chin
g m
ovem
ents
wer
e fa
vour
ed in
sem
i rec
line
as
oppo
sed
to u
prig
ht, s
upin
e an
d lo
ng le
g si
tting
Met
hodo
logy
Que
stio
nnai
re d
evel
oped
bas
ed
on th
e ac
tiviti
ed o
f dai
ly iv
ing
that
wer
e es
tabl
ishe
d fo
r fa
mili
es w
ith c
hild
ren
betw
een
3 m
onth
s and
3 y
ears
old
.
10 q
uest
ionn
aire
s dis
tribu
ted
in
Engl
and;
3 o
btai
ned
via
inte
rvie
w w
ith p
aren
ts in
ch
ildre
ns w
ard
in h
pspi
tal i
n N
. Ir
elan
d: 1
00 d
istri
bute
d to
thos
e un
derg
oing
or h
ad u
nder
gone
tre
atm
ent a
t the
hos
pita
l.
Rea
chin
g m
ovem
ents
wer
e as
sess
ed v
ia si
mul
tane
ous
reco
rdin
g of
vid
eo d
ata
and
surf
ace
EMG
of a
rm, n
eck,
tru
nk a
nd le
g m
uscl
es d
urin
g re
achi
ng in
var
ious
pos
ition
s (ly
ing
supi
ne, s
emi-
recl
ine
(45°
), up
right
and
long
leg
sitti
ng).
Parti
cipa
nts
113
affe
cted
fam
ilies
sur
veye
d 38
que
stio
nnai
res r
etur
ned
(34%
re
spon
se ra
te.
7 ch
ildre
n (a
ge ra
nge
4-18
m
onth
s).
3 bo
ys; 4
girl
s
Stud
y D
esig
n
Que
stio
nnai
re (s
emi s
truct
ured
an
d op
en)
Long
itudi
nal
Purp
ose
To id
entif
y pr
oble
ms
rela
ted
to th
e tre
atm
ent (
splin
tage
) of
DD
H in
ord
er o
f prio
rity
in
fam
ilies
of h
ildre
n w
ith
DD
H.
Phys
ical
, em
otio
nal a
nd
soci
al p
robl
ems a
re th
e fo
cus
of th
e re
port.
To a
naly
se th
e ea
rly
deve
lopm
ent o
f pos
tura
l ad
just
men
ts a
ccom
pany
ing
reac
hing
mov
emen
ts in
ch
ildre
n w
ith c
ereb
ral p
alsy
.
Aut
hor /
Dat
e / T
itle
Cox
SL
& K
erno
han
WG
(199
8) .
They
can
not s
it pr
oper
ly o
r mov
e ar
ound
: sea
ting
and
mob
ility
dur
ing
treat
men
t for
dev
elop
men
tal
dysp
lasi
a of
the
hip
in c
hild
ren.
Had
ders
-Alg
ra M
, van
der
Fits
IB
M, S
trem
mel
aar E
F &
Tou
wen
B
CC
(199
9).
Dev
elop
men
t of p
ostu
ral
adju
stm
ents
dur
ing
reac
hing
in
infa
nts w
ith c
ereb
ral p
alsy
.
3
Res
ults
and
Con
clus
ions
Sign
ifica
nt st
atic
cor
rect
ion
of th
e sp
ine
(sco
liotic
) may
be
ach
ieve
d vi
a an
ar
rang
emen
t of l
ater
al p
ads
on a
seat
ing
syst
em a
pply
ing
a 3-
poin
t for
ce sy
stem
to th
e si
des o
f the
bod
y.
A st
atis
tical
sign
ifica
nt
corr
elat
ion
was
obt
aine
d (p
<0.0
1) b
etw
een
the
sitti
ng
lum
bar c
urve
and
the
popl
iteal
ang
le.
This
co
rrel
atio
n w
as le
ss w
hen
stan
ding
. St
udy
conc
lude
s tha
t the
re is
a
corr
elat
ion
betw
een
tight
ha
mst
rings
and
dec
reas
ing
lum
bar l
ordo
sis,
espe
cial
ly in
th
e se
ated
pos
tion
in c
hild
ren
with
cer
ebra
l pal
sy.
Met
hodo
logy
Shap
e of
spin
e m
easu
red
(spi
nous
pro
cess
ang
le in
an
asse
ssm
ent c
hair
(CA
PS II
).
Exer
ted
forc
s on
chai
r mea
sure
d by
ele
ctric
al tr
ansd
ucer
s at
tach
ed to
late
ral s
uppo
rt pa
ds
and
seat
bas
e. M
easu
rem
ents
w
ere
take
n in
3 a
ltern
ativ
e ar
rang
emen
ts: 1
) uns
uppo
rted
uppe
r bod
y 2)
two
late
ral p
ads a
t th
e sa
me
heig
ht 3
) bod
y su
ppor
ted
by 3
-poi
nt fo
rce
syst
em.
The
Cob
b m
etho
d w
as u
sed
to
mea
sure
lum
bar a
nd th
orac
ic
kyph
osis
. St
andi
ng a
nd s
itiin
g la
tera
l spi
ne fi
lms w
ere
obta
ined
. Th
e po
plite
al a
ngle
was
m
easu
red
to a
sses
s ham
strin
g tig
htne
ss.
Parti
cipa
nts
16 su
bjec
ts w
ith sp
astic
cer
ebra
l pa
lsy
9
boys
: 7 g
irls
Man
age
: 14.
7 ye
ars (
rang
e 6.
5-
20.8
). In
clus
ion
crite
ria re
uire
d su
bjec
ts to
be
non-
ambu
lant
, ha
ve a
scol
iosi
s and
requ
ire
spec
ial s
eatin
g w
ithin
thei
r w
heel
chai
r,.
21 p
artic
ipan
ts
Mea
n ag
e: 9
.4 y
ears
old
Stud
y D
esig
n
Pros
pect
ive
stud
y: m
atch
ed
pairs
des
ign
Ret
rosp
ectiv
e cl
inic
al a
nd
radi
ogra
phic
revi
ew.
Purp
ose
To
inve
stig
ate
the
effe
cts o
f sp
ecia
l sea
ting
on la
tera
l sp
inal
cur
vatu
re in
the
non-
ambu
lant
spas
tic c
ereb
ral
pals
y po
pula
tion
with
sc
olio
sis.
To
ass
ess t
he in
fluen
ce o
f tig
ht h
amst
rings
on
the
sagg
ital a
lignm
ent o
f the
th
orac
ic a
nd lu
mba
r spi
ne in
ch
ildre
n w
ith c
ereb
ral p
alsy
.
Aut
hor /
Dat
e / Y
ear
Hol
mes
KJ,
Mic
hhae
l SM
& T
horp
e (2
003)
. M
anag
emen
t of s
colio
sis w
ith
spec
ial s
eatin
g fo
r the
non
-am
bula
nt
spas
tic c
ereb
ral p
alsy
pop
ulat
ion
– a
biom
echa
nica
l stu
dy.
McC
arth
y JJ
& B
etz
RR
(200
0)
The
rela
tions
hip
betw
een
tight
ha
mst
rings
and
lum
bar h
ypol
ordo
sis
in c
hild
ren
with
cer
ebra
l pal
sy.
4
Res
ults
and
Con
clus
ions
Sign
ifica
nt b
etw
een
grou
p di
ffer
ence
s wer
e ob
serv
ed o
n m
ost d
epen
dent
mea
sure
s.
No
sign
ifica
nt d
iffer
ence
a
coul
d be
attr
ibut
ed to
seat
in
clin
atio
n, h
owev
er a
utho
rs
sugg
est a
nter
ior t
ilt m
ay
dist
urb
post
ural
stab
ility
, w
ithou
t im
prov
ing
uppe
r ex
trem
ity fu
nctio
n..
A si
gnifi
cant
rela
tions
hip
was
fo
und
betw
een
the
prev
alen
ce
of re
tt sy
ndro
me
scol
iosi
s and
or
thop
aedi
c ris
k fa
ctor
s. T
he
findi
ngs s
ugge
st a
trea
tmen
t ap
proa
ch fo
cusi
ng o
n ba
lanc
ing
bila
tera
l mus
cle
pull.
Met
hodo
logy
Seat
surf
ace
incl
inat
ions
of
0°,
5° (a
nter
ior t
ilt),
5° p
oste
rior
tilt)
with
seat
to b
ackr
est a
ngle
at
90°
wer
e co
mpa
red
with
in
and
betw
een
grou
ps, w
ith le
g re
st p
ositi
on a
t 90°
from
the
seat
su
rfac
e fo
r all
expe
rimen
tal
cond
ition
s.
400
ques
tionn
aire
s wer
e di
strib
uted
via
pos
t, 26
2 w
ere
com
plet
ed a
nd re
turn
ed (6
6%).
22
8 w
ere
suita
ble
for s
tatis
tical
an
alys
is (
57%
).
Res
pons
es w
ere
scor
ed
inde
pend
ently
by
two
inve
stig
ator
s..
Parti
cipa
nts
20 c
hild
ren
(10
non-
impa
ired:
10
mild
-mod
erat
e sp
astic
ce
rebr
al p
alsy
. A
ge ra
nge:
4-1
5 ye
ars.
C
P ch
ildre
n ab
le to
sit
inde
pend
ently
and
am
bula
te
with
or w
ithou
t mob
ility
aid
s.
Abl
e to
com
preh
end
sim
ple
inst
ruct
ions
. Sc
reen
ed fo
r vis
ual p
robl
ems.
262
ques
tionn
aire
s com
plet
ed
by In
tern
atio
nal R
ett S
yndr
ome
Ass
ocia
tion
fam
ilies
. Fi
ndin
gs b
ased
on
57%
resp
onse
ra
te.
Stud
y D
esig
n
Qua
si-e
xper
imen
tal d
esig
n
Que
stio
nnai
re
Purp
ose
To in
vest
igat
e th
e in
ter-
rela
tions
hip
of se
at-s
urfa
ce
incl
inat
ion
on p
ostu
ral
stab
ility
and
func
tiona
l use
of
the
uppe
r ext
rem
ities
in
child
ren
with
cer
ebra
l pal
sy.
To in
vest
igat
e th
e in
terr
elat
ions
hips
bet
wee
n re
tt sy
ndro
me
scol
iosi
s and
sy
mm
etric
, asy
mm
etric
m
otor
pul
l, am
bula
tion
and
adva
ncem
ent o
f age
in
orde
r to
pro
vide
a tr
eatm
ent
ratio
nale
for s
low
ing
the
prog
ress
ion
of a
scol
iosi
s.
Aut
hor /
Dat
e / T
itle
McC
lena
gaha
n B
A,
Thom
bs L
&
Miln
er M
(199
2).
Effe
cts o
f sea
t-su
rfac
e in
clin
atio
n on
pos
tura
l sta
bilit
y an
d fu
nctio
n of
th
e up
per e
xtre
miti
es o
f chi
ldre
n w
ith c
ereb
ral p
alsy
.
McC
lure
MK
, Bat
tagl
ia C
&
McC
lure
RJ (
1997
).
The
rela
tions
hip
of c
umul
ativ
e m
otor
asy
mm
etrie
s to
scol
iosi
s in
rett
synd
rom
e.
5
Res
ults
and
Con
clus
ions
Qua
ntifi
able
and
qua
litat
ive
betw
een
grou
p di
ffer
ence
s in
reac
hing
. N
o si
gnifi
cant
di
ffer
ence
s cou
ld b
e at
tribu
ted
to th
e se
atin
g po
sitio
ns.
Sign
ifica
nt d
iffer
ence
s ob
serv
ed a
mon
g th
e fiv
e co
nditi
ons.
Stu
dy su
gges
ts a
an
terio
r sitt
ing
post
ure
is th
e pr
efer
red
posi
tion
to fa
cilit
ate
incr
ease
d tru
nk e
xten
sion
.
Met
hodo
logy
Arm
mov
emen
ts w
ere
com
pare
d be
twee
n gr
oups
and
with
in
grou
ps in
four
diff
eren
t po
sitio
ns (n
eutra
l, w
heel
chai
r, po
ster
ior t
illt (
15°)
and
ant
erio
r til
t (15
°).
Four
con
ditio
ns
pres
ente
d in
cou
nter
bala
nced
or
der.
EM
G a
ctiv
ity re
core
ded.
Each
chi
ld ra
ted
on a
scal
e of
1-
4 to
doc
umen
t tru
nk c
ontro
l, ra
ted
by a
n ex
perie
nced
pa
edia
tric
phys
ioth
erap
ist.
Trun
k ex
tens
ion
mea
sure
s by
the
mod
ified
Sch
ober
M
easu
rem
ent o
f Spi
nal
Exte
nsio
n (1
975)
. Te
sted
in 5
rand
om p
ositi
ons
durin
g 30
min
sess
ion
(flo
or
sitti
ng in
tailo
r lik
e fa
shio
n,
leve
l sitt
ing
with
hip
s and
kne
es
at 9
0°, b
ench
sitti
ng w
ith b
ench
til
ted
forw
ard
(20°
and
30°)
and
si
tting
in
a co
mm
erci
al c
hair.
Parti
cipa
nts
12 su
bjec
ts
3 m
en: 3
wom
en w
ith m
ild-
mod
erat
e sp
astic
cer
ebra
l pal
sy;
3 m
en a
nd 3
wom
en w
ith n
o kn
own
path
olog
ical
con
diti
on.
Age
rang
e; 1
8-21
yea
rs
Rig
ht h
and
dom
inan
t A
ble
to fo
llow
inst
ruct
ions
15 c
hild
ren
Age
rang
e (2
-6 y
ears
) D
iagn
osis
of d
evel
opm
enta
l de
lay
and/
or se
vere
hyp
oton
ic o
r hy
perto
nic
cere
bral
pal
sy
(dip
legi
a or
qua
drip
legi
a).
Stud
y D
esig
n
Qua
si-e
xper
imen
tal
Purp
ose
To c
ompa
re a
rm m
ovem
ents
of
per
sons
with
and
with
out
cere
bral
pal
sy a
nd to
de
term
ine
if th
e al
tera
tion
of
the
seat
ang
le o
f a c
hair
affe
ct
qual
ity o
f mov
emen
ts.
To id
entif
y a
relia
ble,
ob
ject
ive
and
clin
ical
ly
usef
ul m
easu
re fo
r ass
essi
ng
chan
ges i
n tru
nk a
lignm
ent
and
to e
valu
ate
whi
ch o
f fiv
e di
ffer
ent s
eate
d po
sitio
ns w
as
the
mos
t eff
ectiv
e in
en
cour
agin
g tru
nk e
xten
sion
.
Aut
hor /
Dat
e / T
itle
McP
hers
on JJ
, Sch
ild R
, Spa
uldi
ng
SJ, B
aras
amia
n P,
Tra
nson
C &
W
hite
SC
(199
1).
Ana
lysi
s of u
pper
ext
rem
ity
mov
emen
t in
four
sitti
ng p
ositi
ons:
a
com
paris
on o
f per
sons
with
and
w
ithou
t cer
ebra
l pal
sy.
Mie
dane
r JA
(199
0).
The
effe
cts o
f sitt
ing
posi
tions
on
trunk
ext
ensi
on fo
r chi
ldre
n w
ith
mot
or im
pairm
ent.
6
Res
ults
and
Con
clus
ion
Gre
ates
t red
uctio
n of
sp
astic
ity g
aine
d an
d po
stur
al
cont
rol e
nhan
ced
whe
n th
ree
fact
ors w
ere
com
bine
d:
sym
met
rical
fixa
tion
of b
elt
unde
r sea
t, us
e of
an
abdu
ctio
n or
thos
is a
nd
plac
emen
t in
the
FSP.
Thi
s is
in a
dditi
on to
seat
incl
ined
fo
rwar
ds a
nd a
rms s
uppo
rted
on a
tabl
e.
No
disc
erna
ble
effe
cts w
ere
iden
tifie
d by
seat
in
clin
atio
n al
one.
Res
ults
sugg
est p
atho
logi
cal
mov
emen
ts a
re m
inim
ised
an
d po
stur
al c
ontro
l and
up
per e
xtre
mity
func
tion
are
mor
e 3e
ffic
ient
in a
forw
ard
tippe
d se
at, w
ith a
firm
ba
ckre
st su
ppor
ting
pelv
is,
arm
s sup
porte
d ag
ains
t a
tabl
e an
d fe
et p
erm
itted
to
mov
e ba
ckw
ard.
Met
hodo
lgy
Bot
h ch
ildre
n fil
med
and
ph
otog
raph
ed in
divi
dual
ly in
six
posi
tions
on
the
sam
e oc
casi
on,
incl
udin
g si
tting
in th
eir o
wn
adap
ted
chai
rs a
nd in
the
prop
osed
FSP
. Te
stin
g co
nditi
ons w
ere
alte
red
by
chan
ging
the
seat
incl
inat
ion,
us
e/no
n-us
e of
abd
uctio
n or
thos
is a
nd w
ith.w
ithou
t a ta
ble
in fr
ont o
f the
m.
Tot
al ti
me
for
post
ural
con
trol w
as re
cord
ed
and
path
olog
ical
mov
emen
ts
wer
e co
unte
d.
Chi
ldre
n w
ere
film
ed a
nd
phot
ogra
phed
in 6
pos
ition
s (a
dapt
ed c
hair;
ada
pted
cha
ir an
d cu
t out
leve
l tab
le in
font
of
child
,; FS
P w
ithou
t abd
uctio
n or
thos
is; a
dapt
ed c
hair
and
abdu
ctio
n or
thos
is,;F
SP w
ithou
t ta
ble;
FSP
with
tabl
e an
d ab
duct
ion
orth
osis
). In
FSP
seat
w
as fo
rwar
d in
clin
ed.
Hea
d co
ntro
l, pa
thol
ogic
al
mov
emen
ts, p
ostu
ral c
ontro
l w
ere
mea
sure
d vi
a ob
serv
atio
n an
d Si
tting
Ass
essm
ent S
cale
.
Parti
cipa
nts
2 ch
ildre
n w
ith se
vere
cer
ebra
l pa
lsy.
C
hild
A: 7
yea
rs o
ld, s
past
ic
dipl
egia
C
hild
B: 1
5 ye
ars o
ld ,
spas
tic
tetra
pleg
ia.
23 c
hild
ren
(8 fe
mal
e, 1
5 m
ale)
A
ge ra
nge
(2-1
6 ye
ars)
Stud
y D
esig
n
Pilo
t stu
dy (s
ingl
e ca
se d
esig
n)
Qua
si-e
xper
imen
tal
Purp
ose
To c
reat
e a
func
tiona
l sitt
ing
posi
tion
(FSP
) by
iden
tifyi
ng
the
esse
ntia
l fac
tors
requ
ired
to re
duce
spas
ticity
as w
ell
as e
nhan
cing
pos
tura
l con
trol
in c
hild
ren
with
cer
ebra
l pa
lsy.
To fi
nd a
func
tiona
l sitt
ing
posi
tion
for c
hild
ren
with
ce
rebr
al p
alsy
and
to c
ompa
re
this
pos
ition
with
the
child
ren’
s orig
inal
sitti
ng
posi
tions
with
var
ious
ex
perim
enta
l pos
ition
s.
Aut
hor /
Dat
e / T
itle
Myh
r U &
von
Wen
dt (1
990)
. R
educ
ing
spas
ticity
and
enh
anci
ng
post
ural
con
trol f
or th
e cr
eatio
n of
a
func
tiona
l sitt
ing
posi
tion
in
child
ren
with
cer
ebra
l pal
sy: a
pilo
t st
udy.
Myh
r U &
von
Wen
dt (1
991)
. Im
prov
emen
t of f
unct
iona
l sitt
ing
posi
tion
for c
hild
ren
with
cer
ebra
l pa
lsy.
7
Res
ults
and
Con
clus
ions
Res
ults
reve
aled
that
in
posi
tions
with
the
back
rest
ve
rtica
l and
with
the
use
of a
hi
p be
lt, a
ll ch
ildre
n he
ld
thei
r fee
t pos
terio
r to
the
knee
join
t axi
s reg
ardl
ess o
f se
at in
clin
atio
n.
8 ou
t of t
he 1
0 ch
ildre
n as
sess
ed, w
ho u
sed
the
FSP
over
the
five
year
per
iod,
sh
owed
slig
ht b
ut si
gnifi
cant
im
prov
emen
t, th
e re
mai
ning
tw
o ch
ildre
n ha
d de
terio
rate
d.
Stud
y co
nclu
des t
hat t
he F
SP
cont
ribut
es to
impr
oved
ab
ility
to u
se th
e up
per
extre
miti
es (h
and
and
arm
fu
nctio
n).
Met
hodo
logy
The
child
ren
wer
e fil
med
and
ph
otog
raph
ed w
hils
t per
form
ing
stan
dard
ised
task
s in
5 di
ffer
ent
sitti
ng p
ositi
ons (
back
rest
ve
rtica
l and
sea
t sur
face
in
clin
atio
n va
ryin
g be
twee
n 0°
10
° for
war
d in
clin
ed, 1
0°
back
war
d re
clin
ed, a
nd a
lso
in
recl
ined
pos
ition
s in
with
seat
an
d ba
ckre
st l
ean
back
war
d fr
om th
e ho
rizon
tal p
lane
and
ve
rtica
l pla
ne, r
espe
ctiv
ely
(1
5 °)
.
Ten
child
ren
wer
e fil
med
and
ph
otog
raph
ed a
fter t
he
intro
duct
ion
of th
e FS
P an
d su
bseq
uent
ly fi
ve y
ears
late
r. H
ead,
trun
k, fo
ot c
ontro
l, ar
m
and
hand
func
tion
wer
e as
sess
ed
by th
e Si
tting
Ass
essm
ent S
cale
Parti
cipa
nts
10 n
on-d
isab
led
child
ren
(7 g
irls;
3 b
oys)
M
ean
age
6.7
year
s (ra
nge:
4-9
ye
ars)
.
10 c
hild
ren
with
CP
Stud
y D
esig
n
Cas
e St
udy
Ret
rosp
ectiv
e
Purp
ose
To d
eter
min
e th
e sp
onta
neou
s pos
ition
ing
of
the
low
er e
xtre
miti
es re
lativ
e to
the
mov
emen
t axi
s at t
he
knee
join
t, an
d to
det
erm
ine
thre
ext
ent o
f spo
ntan
eous
us
e of
the
arm
s for
supp
ort i
n di
ffer
ent s
ittin
g po
sitio
ns, i
n
a gr
oup
of n
on-d
isab
led
child
ren.
To
obt
ain
a ba
selin
e co
mpa
rison
with
m
easu
rem
ents
of c
hild
ren
with
cer
ebra
l pal
sy.
To re
-ass
ess c
hild
ren
who
w
ere
prev
ious
ly in
trodu
ced
to
and
test
ed in
the
FSP
five
year
s pre
viou
sly.
To
re-e
xam
ine
the
relia
bilit
y of
the
Sitti
ng A
sses
smen
t Sc
ale.
Aut
hor /
Dat
e / T
itle
Myh
r U (1
994)
. In
fluen
ce o
f diff
eren
t sea
t and
ba
ckre
st in
clin
atio
ns o
n th
e sp
onta
neou
s pos
ition
ing
of th
e ex
trem
ities
of n
on-d
isab
led
child
ren.
Myh
r U, v
on W
endt
L, N
orrli
n S
&
Rad
ell U
(199
5).
Five
yea
r fol
low
-up
of fu
nctio
nal
sitti
ng p
ositi
on in
chi
ldre
n w
ith
cere
bral
pal
sy.
8
Res
ults
and
Con
clus
ions
Res
ults
of t
he st
udy
sugg
est
that
pul
mon
ary
func
tion
was
hi
gher
in a
dapt
ive
seat
ing
com
pare
d to
non
-ada
ptiv
e se
atin
g.
Res
ults
sugg
est i
mpl
icat
ions
fo
r spe
ech,
sitti
ng fo
r pr
olon
ged
perio
ds a
nd th
e pr
even
tion
of p
ulm
onar
y hy
perte
nsio
n.
Res
ults
hig
hlig
hted
that
ex
tens
or a
ctiv
ity w
as lo
wes
t w
hen
back
rest
incl
inat
ion
rem
aine
d at
90°
and
the
seat
su
rfac
e at
0° (
uprig
ht si
tting
). Pr
elim
inar
y fin
ding
from
st
udy
sugg
ests
that
the
orie
ntat
ion
of th
e he
ad
/nec
k/bo
dy in
rela
tion
to
grav
ity m
ay p
lay
an
impo
rtant
role
in c
ontro
lling
ex
tens
or a
ctiv
ity.
Met
hodo
logy
Vita
l cap
acity
, for
ced
expi
rato
ry
volu
me
in o
ne se
cond
, and
ex
pira
tory
tim
e as
mea
sure
by
a sp
irom
eter
, of
chi
ldre
n w
ith C
P w
ere
mea
sure
d in
a ty
pica
l slin
g ba
ck w
heel
chai
r and
in a
w
heel
chai
r with
mod
ular
inse
rts.
Chi
ldre
n w
ere
posi
tione
d in
90
-90-
90 in
bot
h se
atin
g un
its.
Usi
ng su
rfac
e el
ectro
des E
MG
ac
tivity
was
reco
rded
for t
he
lum
bar e
xten
sor s
pina
e m
uscl
es
in se
ven
diff
eren
t tes
ting
cond
ition
s. S
eat s
urfa
ce
incl
inat
ions
of 0
° and
15°
co
mbi
ned
with
bac
kres
t in
clin
atio
ns o
f 75°
, 90°
, 105
°, an
d 12
0°..
Parti
cipa
nts
8 ch
ildre
n w
ith sp
astic
CP
A
ge ra
nge:
5-1
2.
Non
-am
bula
nt
No
appa
rent
evi
denc
e of
in
trins
ic lu
ng d
isea
se.
11 c
hild
ren
(7 b
oys:
4 g
irls)
w
ith sp
astic
CP.
A
ge ra
nge:
4-8
yea
rs
Stud
y D
esig
n
Qua
si-E
xper
imen
tal
Expe
rimen
tal
Purp
ose
To c
ompa
re th
e ef
fect
s of
adap
tive
and
non
adap
tive
seat
ing
on p
ulm
onar
y fu
nctio
n.
To d
eter
min
e if
the
myo
elec
tric
activ
ity o
f the
ex
tens
or m
uscl
es o
f the
lu
mba
r spi
ne is
aff
ecte
d by
po
sitio
ns o
f the
seat
surf
ace
and
seat
bac
k, o
r by
thei
r po
sitio
ns re
lativ
e to
one
an
othe
r.
Aut
hor /
Dat
e / T
ilte
Nw
aobi
OM
& S
mith
(198
6).
Effe
ct o
f ada
ptiv
e se
atin
g on
pu
lmon
ary
func
tion
of c
hild
ren
with
ce
rebr
al p
alsy
.
Nw
aobi
OM
, Bru
bake
r CE,
Cus
ick
B &
Sus
sman
(198
3).
Elec
trom
yogr
aphi
c in
vest
igat
ion
of
exte
nsor
act
ivity
in c
ereb
ral-
pals
ied
child
ren
in d
iffer
ent s
eatin
g po
sitio
ns.
9
Res
ults
and
Con
clus
ions
Res
ults
dem
onst
rate
d th
at
mus
cle
activ
ity w
as a
ffec
ted
by b
ody
orie
ntat
ion,
with
to
nic
mus
cle
activ
ity lo
wer
in
the
uprig
ht p
ositi
on w
ith
stat
istic
ally
sign
ifica
nt
diff
eren
ces f
or th
e hi
p ad
duct
ors a
nd b
ack
exte
nsor
s.
Exte
nsor
tone
may
incr
ease
in
the
recl
ined
pos
ition
.
Res
ults
con
clud
e or
ient
atio
n of
the
body
in sp
ace
affe
cts
uppe
r ext
rem
ity fu
nctio
n.
The
leve
l of u
pper
ext
rem
ity
perf
orm
ance
was
hig
hest
in
the
uprig
ht p
ositi
on.
Met
hodo
logy
Surf
ace
elec
trode
s wer
e us
ed to
m
easu
re m
yoel
ectri
c ac
tivity
if
the
low
bac
k ex
tens
ors,
hip
addu
ctor
s and
ank
le p
lant
ar
flexo
r mus
cles
in tw
o se
atin
g po
sitio
ns.
Th
e se
atin
g po
sitio
ns w
ere
0° in
ve
rtica
l pla
ne a
nd 3
0° fr
om th
e ve
rtica
l pla
ne.
Each
par
ticip
ant
was
pos
ition
ed
in 9
0-90
-90
with
th
e us
e of
a p
omm
el p
rior t
o te
stin
g.
The
child
ren
wer
e pl
aced
ra
ndom
ly in
dif
fere
nt se
atin
g or
ient
atio
ns (3
0°, 1
5°, a
nd 0
° po
ster
ior i
nclin
atio
n an
d 15
°ant
erio
r inc
linat
ion)
.
Parti
cipa
nts
12 c
hild
ren
(8 b
oys:
4 g
irls)
A
ge ra
nge:
6-1
8 ye
ars
Dia
gnos
is o
f mild
-mod
erat
e sp
astic
dip
legi
a.
Fair
head
and
trun
k co
ntro
l Fa
ir to
poo
r fin
e m
otor
skill
s N
o fix
ed d
efor
mity
. 13
chi
ldre
n w
ith C
P
3 at
heto
id C
P 10
spas
tic C
P A
ge ra
nge:
8-1
6 ye
ars
Una
ble
to a
mbu
late
in
depe
nden
tly
Req
uire
ada
ptiv
e se
atin
g fo
r up
right
pos
ition
ing
Fair-
poor
gro
ss u
pper
ext
rem
ity
cont
rol.
Fair
head
and
trun
k co
ntro
l Po
or fi
ne m
otor
skill
s.
Stud
y D
esig
n
Expe
rimen
tal
Qua
si-e
xper
imen
tal
Purp
ose
To m
easu
re th
e to
nic
myo
elec
tric
activ
ity o
f the
lo
w b
ack
exte
nsor
s, hi
p ad
duct
ors a
nd a
nkle
pla
ntar
fle
xors
in tw
o bo
dy
orie
ntat
ions
. To
det
erm
ine
if to
nic
activ
ity
of th
ese
mus
cles
cha
nge
in
resp
onse
to b
ody
orie
ntat
ion,
an
d w
hich
bod
y or
ient
atio
n pr
ovid
es th
e lo
wes
t lev
el o
f m
uscl
e ac
tivity
.
To m
easu
re th
e pe
rfor
man
ce
time
of a
pre
scrib
ed u
pper
ex
trem
ity a
ctiv
ity in
four
di
ffer
ent s
eatin
g or
ient
atio
ns
rela
tive
to th
e ve
rtica
l pla
ne
to d
eter
min
e th
e ef
fect
of
body
orie
ntat
ion
on v
olun
tary
m
otor
func
tion.
Aut
hor /
Dat
e / T
itle
Nw
aobi
UM
(198
6).
Effe
cts o
f bod
y or
ient
atio
n in
spac
e on
toni
c m
uscl
e ac
tivity
of p
atie
nts
w
ith c
ereb
ral p
alsy
.
Nw
aobi
OM
(198
7).
Seat
ing
orie
ntat
ions
and
upp
er
extre
mity
func
tion
in c
hild
ren
with
ce
rebr
al p
alsy
.
10
Res
ults
and
Con
clus
ion
The
sadd
le se
at h
as th
e po
tent
ial t
o m
odify
the
qual
ity o
f sea
ting
post
ure
and
reac
hing
mov
emen
ts in
ch
ildre
n w
ith c
ereb
ral p
alsy
. Sa
ddle
ben
ch a
llow
ed
impr
oved
pos
tura
l con
trol a
s m
easu
red
by th
e Si
tting
A
sses
smen
t for
Chi
ldre
n w
ith
Neu
rom
otor
Dys
func
tion.
Res
ults
con
clud
e th
at n
o si
gnifi
cant
diff
eren
ces i
n re
spira
tory
par
amet
ers w
ere
attri
bute
d to
seat
incl
inat
ion
in
eith
er th
e no
rmal
gro
up o
r th
ose
with
CP.
R
esul
ts su
gges
t how
ever
that
in
crea
sed
tidal
vol
ume
and
min
ute
vent
ilatio
n m
ay
incr
ease
d in
ant
erio
r tip
ped
seat
ing,
alth
ough
are
not
st
atis
tical
ly si
gnifi
cant
.
Met
hodo
logy
The
two
expe
rimen
tal c
ondi
tions
w
ere
the
sadd
le se
at (1
5°
forw
ards
incl
inat
ion)
and
a fl
at
woo
den
benc
h.
Clin
ical
ass
essm
ent o
f sea
ted
post
ural
con
trol w
as m
easu
red
by th
e Si
tting
Ass
essm
ent f
or
Chi
ldre
n w
ith N
euro
mot
or
Dys
func
tion.
Res
pira
tion
para
met
ers o
f tid
al
volu
me,
resp
iratio
n ra
te a
nd
min
ute
vent
ilatio
n a
re
com
pare
d in
resp
onse
to tw
o se
ated
pos
ition
s 1)
flat
seat
ing
2) a
nter
ior s
eatin
g (1
0° fo
rwar
d tip
ped)
. R
espi
rato
ry in
duct
ance
pl
ethy
smog
raph
y us
ed to
reco
rd
resp
irato
ry fu
nctio
n.
Parti
cipa
nts
6 ch
ildre
n w
ith m
ild-m
oder
ate
spas
tic C
P.
Abl
e to
sit o
n a
flat b
ench
w
ithou
t hol
ding
on.
In
depe
nden
tly m
obile
via
use
of
wal
ker o
r man
ual w
heel
chai
r.
12 c
hild
ren
(6 n
on-im
paire
d,
mea
n ag
e 9.
7 ; 6
with
spa
stic
C
P), m
ean
age
6.0)
C
hild
ren
with
CP
able
to
ambu
late
eith
er w
ith o
r with
out
mob
ility
aid
s
Stud
y D
esig
n
Rep
eate
d-m
easu
res
expe
rimen
tal c
ross
-ove
r des
ign.
Expe
rimen
tal
Purp
ose
To e
valu
ate
post
ural
con
trol
and
uppe
r ext
rem
ity
mov
emen
t con
trol i
n ch
ildre
n w
ith c
ereb
ral p
alsy
usi
ng a
sa
ddle
seat
.
To in
vest
igat
e th
e ef
fect
s of
usin
g an
ant
erio
r inc
lined
seat
ba
se o
n tid
al v
olum
e,
resp
iratio
n ra
te a
nd m
inut
e ve
ntila
tion
func
tion
of
norm
al c
hild
ren
and
child
ren
with
cer
ebra
l pal
sy.
Aut
hor /
Dat
e / T
itle
Rei
d D
T (1
996)
Th
e ef
fect
s of t
he sa
ddle
seat
on
seat
ed p
ostu
ral c
ontro
l and
upp
er
extre
mity
mov
emen
t in
child
ren
with
cer
ebra
l pal
sy.
Rei
d D
T &
Soc
hani
wsk
j (19
91).
Ef
fect
s of a
nter
ior t
ippe
d se
atin
g on
re
spira
tory
func
tion
of n
orm
al
child
ren
and
child
ren
with
cer
ebra
l pa
lsy.
11
Res
ults
and
Con
clus
ion
Res
ults
con
clud
e de
velo
pmen
t of p
ostu
ral
adju
stm
ent d
urin
g re
achi
ng is
no
n-lin
ear a
nd n
ot fi
nish
ed
until
11
year
s old
. A
ntic
ipat
ory
post
ural
mus
cle
activ
ity ,
cons
iste
ntly
pre
sent
in
adu
lts, w
as b
asic
ally
ab
sent
bet
wee
n 2-
11 y
ears
. Fi
ndin
gs su
gges
t tha
t the
fo
rwar
d til
ted
sitti
ng p
ositi
on
is th
e m
ost e
ffic
ient
rega
rdin
g po
stur
al c
ontro
l. R
esul
ts sh
ow th
at to
nal
sym
met
ry is
rela
ted
to
win
dsw
ept d
efor
mity
alo
ne,
whe
reas
incr
ease
d ag
e, se
vere
sp
astic
ity, a
nd d
irect
ion
of
tona
l asy
mm
etry
wer
e as
soci
ated
with
win
dsw
ept
defo
rmity
and
hip
di
sloc
atio
n.
Prev
alen
ce ra
tes i
nclu
ded
52%
(win
dsw
ept h
ips)
, 25%
(to
nal a
sym
met
ry),
in h
ip
subl
uxat
ion
(63%
) and
hip
su
rger
y (6
3%).
The
side
with
th
e st
rong
est t
one
was
mor
e fr
eque
ntly
dis
loca
ted
of h
eld
in fi
xed
addu
ctio
n.
Met
hodo
logy
29 c
hild
ren
and
10 a
dults
stud
ies
via
EMG
and
kin
emat
ics d
urin
g re
achi
ng in
4 d
iffer
ent
cond
ition
s: si
tting
with
seat
su
rfac
e ho
rizon
tal,
with
and
w
ithou
t tas
k lo
ad, 1
5° fo
rwar
d
of se
at su
rfac
e an
d 15
° ba
ckw
ards
tilt
of se
at su
rfac
e
Dat
a ga
ther
ed fo
rm m
edic
al
reco
rds a
nd p
hysi
cal
exam
inat
ion
(sta
ndar
dise
d)
Parti
cipa
nts
29 h
ealth
y ch
ildre
n, a
ge ra
nge
2-11
. 10
you
ng a
dults
(mea
n ag
e 23
.6±2
yea
rs)
103
subj
ects
with
spas
tic C
P re
crui
ted
from
two
stud
y in
stitu
tions
.
Stud
y D
esig
n
Expe
rimen
tal
Cro
ss-s
ectio
nal s
tudy
Purp
ose
To
inve
stig
ate
the
deve
lopm
ent o
f pos
tura
l ad
just
men
ts a
ccom
pany
ing
reac
hing
mov
emen
ts in
si
tting
chi
ldre
n.
To d
eter
min
e th
e pr
eval
ence
of
win
dsw
ept h
ip d
efor
mity
an
d hi
p di
sloc
atio
n, a
nd th
eir
rela
tions
hip
to a
sym
met
ry o
f m
uscl
e to
ne.
Aut
hor /
Dat
e / T
itle
Van
der
Hei
de JC
, Ote
n B
, van
Ey
kern
LA
& H
adde
rs-A
lgra
(2
003)
. D
evel
opm
enta
l of p
ostu
ral
adju
stm
ents
dur
ing
reac
hing
in
sitti
ng c
hild
ren.
You
ng N
L, W
right
JG, L
am T
P,
Raj
arat
nam
K, S
teph
ens D
, &
Wed
ge JH
(199
8).
Win
dsw
ept d
efor
mit
y in
spas
tic
quad
riple
gic
cere
bral
pal
sy.