Post on 18-Mar-2022
transcript
Instructions for ISS 2013 Pre-Conference Course PC3
Measuring Wheelchair Seated Posture and Seating Supports: A Practicum
Kelly Waugh, PT, MAPT, ATP Dr. Barbara Crane, PT, PhD, ATP/SMS
Handouts posted on ISS website include:
1. Course Agenda 2. PDF of Power Point lecture 3. Link to the Clinical Application Guide: http://at-partners.org/WheelchairSeating
The manual titled Clinical Application Guide to Standardized Wheelchair Seating Measures of the Body and Seating Supports, upon which this course is based, is a very large resource (over 300 pages); therefore you do not need to print it out as a “handout”. As an alternative, the following is recommended:
1. Download the PDF from the Assistive Technology Partners website, and bring the electronic PDF file with you on a laptop or tablet if at all possible.
• We will be dividing the class up into 10 groups; we are hoping that there will be at least one participant with a laptop in each group.
• We will project the relevant pages and measures onto the screen during the practicum; however, your learning experience will be enhanced if you are able to bring a laptop with you to the course. This will allow you to practice navigating through this large manual, and it will be easier to see and follow the written methodologies during the hands-on portions.
2. As an alternative to #1, you can print out the relevant pages of the guide, which are listed on the Course Agenda.
3. Please also bring the following if you have them:
• ½” metal tape measure • 180 degree goniometer without a large dial in the middle • Inclinometer (non-digital)
If you have any questions, please contact me by email:
Kelly.waugh@ucdenver.edu
Regards,
Kelly Waugh 2/19/13
Kelly Waugh, PT, MAPT, ATP AGENDA_Seating Measurement_ISS 2013.docx Page 1 of 2
Measuring Wheelchair Seated Posture and Seating Supports: A Practicum
Kelly Waugh, PT, MAPT, ATP & Barbara Crane, PT, PhD, ATP/SMS
ISS 2013 Pre-Conference Course PC3, 3/5/2013
Time Topic Handout/Measures 8:00am – 9:45am
Introduction to the Clinical Application Guide and Foundational Concepts
PDF of power point
9:45am – 10:00am
Relative Body Segment Angles, Demo
10:00 – 10:15am
Break
10:15am – 11:00am
Relative Body Segment Angles Practicum
Clinical Guide Ch. 2, pp. 44-54 Thigh to trunk angle Thigh to lower leg angle Lower leg to foot angle Thigh to pelvis angle
11:00am - 12:00pm
Relative Support Surface Angles
Clinical Guide Ch.3, pp.116-117, 122-127 Seat to back support angle Seat to lower leg support angle Lower leg support/foot support angle
12:00pm – 1:00pm
LUNCH
1:00pm – 2:00pm
Absolute Body Segment Angles
Clinical Guide Ch. 2, pp.80-85, 58-63, 100-102 Frontal Pelvic angle Frontal sternal angle Frontal trunk angle Sagittal pelvic angle Sagittal trunk angle Sagittal thigh angle Transverse thigh angle
2:00pm – 3:00pm
Absolute Support Surface Angles
Clinical Guide Ch. 3, pp. 130-132, 154-156, 164-165, 192-193 Seat sagittal angle Back support sagittal angle Head support frontal angle Lateral knee support transverse angle
3:00pm – 3:15pm
Break
3:15pm – 4:00pm
Linear Body Measures
Clinical Guide Ch. 4, pp.214-215, 223-225 Buttock/thigh depth Effective buttock/thigh depth Shoulder height Max sitting height
Kelly Waugh, PT, MAPT, ATP AGENDA_Seating Measurement_ISS 2013.docx page 2
4:00pm – 5:00pm
Linear Support Surface Measures
Clinical Guide Ch. 5, pp.279-290, 292, 316-319 Seat depth Effective seat depth Seat thickness Inferior thigh support thickness Medial thigh support height Pelvic contour height Back support length Back support height Seat surface to foot support Seat surface to floor height
5:00pm – 5:30pm
Summary / Q & A
Link to: A Clinical Application Guide to Standardized Wheelchair Seating Measures of the Body and Seating Support Surfaces http://at-partners.org/WheelchairSeating Bring to course if possible:
1. Laptop or tablet with the PDF version of above guide loaded 2. ½” metal tape measure 3. 180 degree goniometer, with small center dial 4. Inclinometer (non-digital)
Measuring Wheelchair Seated Posture and Seating Supports ISS 2013
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Measuring Wheelchair Seated Posture
and Seating Supports
Kelly Waugh, PT, MAPT, ATP Senior Instructor/Clinic Coordinator
Assistive Technology Partners
University of Colorado Anschutz Medical Campus
Denver, Colorado, USA
Copyright © 2013, The Regents of the University of Colorado, a body corporate. All rights reserved.
Created by Kelly Waugh, Assistive Technology Partners; supported by Grant #668 from the PVA Education Foundation
Barbara Crane, PT, PhD, ATP/SMS Associate Professor
Department of Rehabilitation Sciences
University of Hartford
Measuring Wheelchair Seated Posture
and Seating Supports
1. Background
2. Overview of the Clinical Guide
3. Foundational Concepts
4. Angular Measures
5. Linear Measures
6. Tools for Measurement
7. Future
Need Identified for Term Standardization
• There is much variation in use of terms to describe and quantify both seated posture and the linear and angular dimensions of person’s seating support surfaces
• This creates barriers to communication between all people involved in wheelchair service delivery process = poor outcomes and inefficiency
• Research on wheelchair seated posture requires standardized measures
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Development of ISO 16840-1:2006
• 1998: U.S. submitted proposal to ISO (International Standards
Organization) to develop an international standard for wheelchair
seating terms and definitions
• 1998 -2006: After 8 years of international collaboration, this standard
was published by ISO:
• ISO 16840-1 (2006): Wheelchair Seating – Vocabulary, reference
axis convention and measures for body posture and postural
support surfaces.
Purpose of ISO 16840-1:2006
1. Objectively describe and measure posture of the wheelchair seated person
2. Quantify angular orientation of seating support surfaces, and be able to relate these to the posture of the person
3. Standardize terms and definitions for linear dimensions of seated person’s body
4. Standardize terms and definitions for linear dimensions of seating support surfaces
Scope of ISO 16840-1: 2006
• Defines a global coordinate system for quantifying measures of a wheelchair-seated person and their seating support surfaces
• Defines measures of the seated person:
– Body Angles
– Linear Measures
• Defines measures of the seating support surfaces:
– Support surface angles
– Linear size measures
– Linear location measures
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Positive Outcomes of ISO16840-1
• It established some foundational principles from which to develop standardized terms and definitions for seating measures
• It has facilitated the development of measurement and recording tools
• Horizon tool and Rysis software, developed in Japan
• It is facilitating research in reliability of the new measures
• Locating body landmarks
• Reliability of measures using the new measurement tools
The negative…….
• There has been minimal adoption and use of the terms and measures defined in ISO 16840-1 by clinicians, wheelchair suppliers, manufacturers and researchers. Why?
The ISO standard is complex and difficult to understand
The ISO standard is expensive and must be purchased
PVA Education Foundation Grant 2011-2012
• In 2011, Waugh awarded grant from Paralyzed Veteran’s of America
(PVA) Education Foundation to fund development of the clinical guide
to the ISO standard.
• Members of the project team:
• Kelly Waugh, PT (Project Director); Dr. Barbara Crane, PT, PhD;
Susan Johnson Taylor, OT; Kim Davis, PT and Susan Cwertnia, PT
• The name of this guide is:
• A Clinical Application Guide To Standardized Wheelchair Seating
Measures Of The Body And Seating Support Surfaces
http://at-partners.org/WheelchairSeating
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Measuring Wheelchair Seated Posture
and Seating Supports
1. Background
2. Overview of the Clinical Guide
3. Foundational Concepts
4. Angular Measures
5. Linear Measures
6. Tools for Measurement
7. Future
Purpose of the Clinical Guide
• “Translate” the content of ISO standard into a resource manual which is easier to understand and apply clinically
• Make the guide available on internet in PDF format, which is free to download, so that everyone has access to it.
Our main goal is to:
• Promote the adoption of standardized terms and measures in the field of wheelchair seating
Table of Contents of the Guide
CHAPTER 1: INTRODUCTION
CHAPTER 2: ANGULAR BODY MEASURES
CHAPTER 3: ANGULAR SUPPORT SURFACE MEASURES
CHAPTER 4: LINEAR BODY MEASURES
CHAPTER 5: LINEAR SUPPORT SURFACE MEASURES
APPENDICES (5)
GLOSSARY
BIBLIOGRAPHY
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The Guide is very comprehensive…..
• 130 terms
• For each measurement term: Description, accurate
definition, clinical relevance, sample measurement
procedure, and 1-3 figures illustrating the measure
• Because most people using wheelchairs have simple
postural support requirements, only a small subset of
these measures would be used in most clinical seating
applications.
The list of measures is not prescriptive…
• Measures are categorized as either a Level 1 or Level 2
measure, to suggest a selection of measures to take
based on complexity of person’s postural deviations and
support needs
• However, the choice of measurements used in any
clinical situation will depend on the complexity of the
person’s postural deviations, as well as the goals of the
measurement process.
Clinical Guide vs. ISO16840-1:2006
• The ISO 16840-1:2006 standard needs to be revised
• The Clinical Guide is based on the anticipated
revisions to the ISO 16840-1 standard
• ISO standard includes only a definition of the
measurement term
• The guide includes sample methodology, lots of
diagrams and clinical relevance
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Measuring Wheelchair Seated Posture
and Seating Supports
1. Background
2. Overview of the Clinical Guide
3. Foundational Concepts
4. Angular Measures
5. Linear Measures
6. Tools for Measurement
7. Future
3 Foundational Concepts
Body segment and seating support terminology
Joint motion terminology & body planes
Describing wheelchair seated posture
Body segment lines
Support surface reference planes and lines
Relative vs. Absolute angles
Reference system
Body segment terminology
Dividing the body into segments
• Can describe seated posture
by measuring orientation of
segments
• Can relate orientation of body
segments to the orientation of
their supporting surface
• Helps define and label
seating supports
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Seating support terminology
• Labeling convention for seating supports:
– Supports are named by the body segment intended to contact,
and the side of the segment where typically placed
• Inferior/superior, anterior/posterior, medial/lateral
– Supports should NOT be labeled by their purpose. The purpose
of the support is client specific, and is dependent on how it is
applied.
• Examples of correct terms:
– Lateral thigh support, not “hip adductor”
– Medial knee support, not “hip abductor”
– Lateral trunk support, not “scoliosis pad”
– Posterior upper arm support, not “elbow block”
Seating support terminology - Exceptions
• If support is segment’s primary weight bearing surface, don’t use the
directional term. For example:
– Head support, not “posterior head support”
– Foot support, not “inferior foot support”
– Seat (not inferior buttock/thigh support)
– Back support (not posterior trunk support)
– Arm support (not inferior forearm support)
Differentiating terms for the body vs. seating
supports vs. wheelchair
• It is critically important to differentiate between measures of the
seated person’s body from measures of the seating support
surfaces, because they are not necessarily the same
• Also important to differentiate terms and measures of the wheelchair
frame from the seating supports
• For example: Seat depth
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3 Foundational Concepts
Body segment and seating support terminology
Joint motion terminology & body planes
Describing wheelchair seated posture
Body segment lines
Support surface reference planes and lines
Relative vs. Absolute angles
Reference system
Joint Motion Terminology & Body Planes
Body movement defined by:
1. The plane through which the body limb moves
• Sagittal
• Frontal
• Transverse
The “Standing Anatomical Position” is the zero reference for joint range of motion values
The Three Body Planes
Postural deviations in the sitting position can also be
described as occurring in these same three planes
• Clinicians often describe postural deviations in sitting by
viewing the client from three perspectives:
• From the side – to observe sagittal plane deviations
• From the front - to observe frontal plane deviations
• From the top – to observe transverse plane deviations
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3 Foundational Concepts
Body segment and seating support terminology
Joint motion terminology & body planes
Describing wheelchair seated posture
Body segment lines
Support surface reference planes and lines
Relative vs. Absolute angles
Reference system
Describing wheelchair seated posture
Using terms for joint motion
Most clinicians use terms for joint motion
to describe postural deviations in the
sitting position.
“Mrs. Jones sits in her wheelchair with a posterior
pelvic tilt, left pelvic obliquity, right pelvic rotation,
trunk leaning to left. Her hips are extended,
abducted and externally rotated.”
Why is this not adequate for our field?
Terms are frequently used inaccurately
Doesn’t provide a measure of orientation in
space
Does not help with prescription of seating
support surface angles
Describing wheelchair seated posture
Using body segment angles
The standard provides a new set of terminology to define and
quantify seated posture which is based on the orientation of
body segments, called body segment angles
By measuring the angular orientation of body segments you
can define the static posture of a seated person.
The corresponding angular measures of the seating support
system are called support surface angles.
The same conventions are used to measure body segment
angles and support surface angles - helps with prescription.
The new terms for Body Segment Angles do not REPLACE standard terms
for joint range of motion, but rather AUGMENT them.
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3 Foundational Concepts
Body segment and seating support terminology
Joint motion terminology & body planes
Describing wheelchair seated posture
Body segment lines
Support surface reference planes and lines
Relative vs. Absolute angles
Reference system
Thigh
Head
Foot
Lower Leg
Pelvis
Neck
Upper Trunk
Trunk
How would you measure the orientation of her body
segments in this plane?
You need to identify a line on each segment in
order to measure its angular orientation
AND, you need to be able to measure its
orientation in each of the three planes
Body
Landmarks
Body
landmarks
were identified
that can be
viewed from
side, front and
top
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Body
Segment
Lines
Lines connecting
the body landmarks
are called Body
Segment Lines.
These are used to
measure the
angular orientation
of the segments
Sagittal head line
Sagittal thigh line
Sagittal lower leg line
Sagittal pelvic line
Sagittal upper trunk line
Sagittal neck line
Sagittal foot line
Body Segment Lines
– Sagittal View
Each body segment
line is labeled based
on the name of the
body segment and
the view
Sample
Body
Segment
Lines –
Frontal view
Frontal right lower leg line
Frontal pelvic line
Frontal head line
Frontal sternal line
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Transverse foot line
Transverse pelvic line
Transverse forearm line
Transverse thigh line
Transverse trunk line
Sample
Body
Segment
Lines –
Transverse
view
Body Segment Lines and Landmarks
• To measure the orientation of a body segment, need to locate a line on the segment, to represent the orientation in each plane
• Body segment lines defined by connecting landmarks
– Sagittal plane (side view)
– Frontal plane (front view)
– Transverse plane (top view)
– Body landmarks must be accessible when seated in wheelchair
• Body Segment Lines joining body landmarks define the body segments and allow measurement of their orientation in each plane
To summarize….
3 Foundational Concepts
Body segment and seating support terminology
Joint motion terminology & body planes
Describing wheelchair seated posture
Body segment lines
Support surface reference planes and lines
Relative vs. Absolute angles
Reference system
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Support Surface Reference Planes and Lines
• To measure the orientation of individual support surfaces, need to
locate a reference line on the contact surface
• Three concepts needed:
• Support surface reference plane
• Support surface geometric center
• Local X, Y, Z axes
• The reference line that is used to measure the orientation of a
seating support is one of the local axes
Z
Y X
3 Foundational Concepts
Body segment and seating support terminology
Joint motion terminology & body planes
Describing wheelchair seated posture
Body segment lines
Support surface reference planes and lines
Relative vs. Absolute angles
Reference system
Relative vs. Absolute Angles
• It is clinically important to be able to define the orientation of a body
segment or support surface in two ways:
1. With respect to an adjacent segment or surface (because this
reflects joint position and common seating angles), and
2. With respect to an external, absolute reference (because this
reflects orientation in space and influence of gravity)
• Therefore, two types of angles are defined
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Relative vs. Absolute Angles
• Relative angles define the angular relationship between
two adjacent body segments, or between two adjacent
seating support surfaces
• Absolute angles define the spatial orientation of a single
body segment or support surface with respect to an
external, absolute reference such as the vertical or
horizontal
Sagittal thigh line
Sagittal trunk line
Thigh to trunk angle = 105 degrees
Example of Relative Angle:
The angle of the trunk relative to the thigh
is called the “Thigh to Trunk Angle”.
This is a relative angle - formed by the
intersection of the sagittal trunk line and
the sagittal thigh line
Absolute Angles:
What if you wanted to measure the
orientation in space of the trunk?
Or the orientation of the thigh?
How would you measure it?
You need a ZERO REFERENCE
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3 Foundational Concepts
Body segment and seating support terminology
Joint motion terminology & body planes
Describing wheelchair seated posture
Body segment lines
Support surface reference planes and lines
Relative vs. Absolute angles
Reference system
Reference system
Coordinate Axis System Convention
The 3 Reference Planes
Wheelchair Axis System
Seated Reference Position
Support Surface Reference Position
Coordinate axis system convention
• Left hand rule convention
• Labeling of axes X, Y, Z
This shows the
axis system
superimposed
on a wheelchair
seating system
and on a seated
person.
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Three reference planes
The three reference planes – Sagittal, Frontal and Transverse - are defined by the coordinate axes
Wheelchair Axis System (WAS)
• The absolute, global reference system to which angular
orientations of the body or support surfaces are
compared for measurement of absolute angles
The Seated Reference Position (SRP)
• SRP = A specified hypothetical zero reference position for seated posture, used to define absolute angular measures of the body, where the body segments are at 90 degrees to one another, and in line with the vertical or horizontal
• In the SRP, body segment lines are parallel to one of the WAS axes
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The Support Surface Reference Position (SSRP)
• SSRP = A specified hypothetical zero reference position for the body support system, used to define absolute angular measures of the support surfaces, where the supports are orthogonal, in line with vertical or horizontal
• In SSRP, the support surface reference axes will always be parallel to one of the WAS axes
Measuring Wheelchair Seated Posture
and Seating Supports
1. Background
2. Overview of the Clinical Guide
3. Foundational Concepts
4. Angular Measures
5. Linear Measures
6. Tools for Measurement
7. Future
4 Angular Measures
Relative vs. Absolute Angles
Relative Angles
Absolute Angles
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Relative vs. Absolute Angles - Body
Relative vs. Absolute Angles –
Seating Support Surfaces
4 Angular Measures
Relative vs. Absolute Angles
Relative Angles
Absolute Angles
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Primary 3 Relative Support Surface Angles
Seat to Back Support Angle
Seat to Lower Leg Support Angle
Lower Leg Support/Foot Support Angle
95°
105°
120°
These angles DO NOT describe the posture of the seated person !
Primary 3 Relative Body Segment Angles
Thigh to Trunk Angle
Thigh to Lower Leg Angle
Lower Leg to Foot Angle
98°
75°
95°
Relationship between Body Segment Angles and Support
Surface Angles
If seated person’s body
segment lines are parallel
to the corresponding
support surface reference
lines, then the body
segment angles will be
the same as the support
surface angles (both
absolute and relative)
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Relative Angles - Determining angular value
• Relative angles measure the angle between adjacent body segments or support
surfaces
• An angle can be measured on either of two sides….which side do you measure?
An angle can be measured on
either of two sides….
…the values add up to 360
degrees
Supplementary angles add up
to 180 degrees
Level I
Level II
Sagittal plane Thigh to trunk angle
Thigh to lower leg angle
Lower leg to foot angle
Thigh to pelvis angle
Relative body segment angles • Relative body segment angles measure the angle between adjacent segments
(currently defined in the sagittal plane only)
The angle between the thigh
and the trunk, viewed from the
side
The angle between the thigh
and the lower leg, viewed from
the side
The angle between the lower
leg and the foot, viewed from
the side
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Thigh to trunk angle
Relationship to hip flexion angle
The angle between the thigh and the
trunk, viewed from the side
…relationship to hip flexion
angle
…relationship to knee flexion angle The angle between the thigh and
the lower leg, viewed from the
side
Thigh to lower leg angle
Relationship to knee flexion angle
The angle between the lower leg and
the foot, viewed from the side …relationship to dorsiflexion angle
Lower leg to foot angle
Relationship to ankle dorsiflexion angle
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Level I
Level II
Sagittal plane Seat to back support angle
Seat to lower leg support angle
Lower leg support to foot support angle
Seat to upper back support angle
Seat to lower back support angle
Relative support surface angles • Relative support surface angles measure the angle between adjacent supports
(currently defined in the sagittal plane only)
The angle between the seat
and the back support, viewed
from the side
The angle between the seat
and the lower leg support,
viewed from the side
The angle between the lower
leg support and the foot
support, viewed from the side
SEAT TO LOWER LEG SUPPORT
ANGLE
LOWER LEG SUPPORT TO FOOT
SUPPORT ANGLE
Seat to lower leg support angle
With and without a posterior lower leg support in place
Seat to lower leg support angle - Definition: The posterior side of the angle formed between the
seat reference plane and the lower leg support reference plane, as viewed from the side
SEAT TO LOWER LEG SUPPORT
ANGLE, no calf pad SEAT TO LOWER LEG SUPPORT
ANGLE, with calf pad
Seat to lower leg support angle - Description: The angle between the seat and the lower
leg support, as viewed from the side
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Seat to lower leg support angle
vs. “wheelchair lower leg support assembly angle”
Seat to lower leg support angle - Definition: The posterior side of the angle formed between the
seat reference plane and the lower leg support reference plane, as viewed from the side
Wheelchair manufacturers label the angle of the “front end” of the wheelchair, which usually
includes the leg support/foot support structure, as either a 60, 70, 80 or 90 degree angle. This
represents the angle between the extension of the seat rail, down to the vertical hanger tube
4 Angular Measures
Relative vs. Absolute Angles
Relative Angles
Absolute Angles
Level I
Level II
Sagittal plane Sagittal Pelvic Angle
Sagittal Trunk Angle
Sagittal Thigh Angle
Sagittal Head Angle
Sagittal Upper Trunk Angle
Sagittal Sternal Angle
Sagittal Abdominal Angle
Sagittal Lower Leg Angle
Sagittal Foot Angle
Frontal plane Frontal Pelvic Angle
Frontal Sternal Angle
Frontal Trunk Angle
Frontal Head Angle
Frontal Lower Leg Angle
Frontal Foot Angle
Transverse plane Transverse Pelvic Angle
Transverse Trunk Angle
Transverse Head Angle
Transverse Thigh Angle
Transverse Foot Angle
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Examples of Absolute Support Surface Angles
Support name Level 1 Measures Level 2 Measures
Seat Seat sagittal angle Seat frontal angle
Seat transverse angle
Foot support
Foot support sagittal angle Foot support frontal angle
Foot support transverse angle
Arm support
Arm support sagittal angle
Arm support frontal angle
Arm support transverse angle
Back support
Back support sagittal angle Back support frontal angle
Back support transverse angle
Head support Head support sagittal angle Head support frontal angle
Head support transverse angle
Lower leg support
Lower leg support sagittal angle Lower leg support frontal angle
Determining the value of an absolute angle
• The absolute angle of an individual body segment or support surface
is the degree to which it has rotated, or deviated away from the zero
reference orientation
• This is measured by comparing the orientation of the body segment
line or support surface reference line to the specified axis of the
Wheelchair Axis System
• Sagittal and Frontal Angles reference the horizontal or vertical
• Transverse Angles reference the wheelchair X axis
Sagittal angles reference
the horizontal or vertical
Frontal angles reference
the horizontal or vertical
Transverse angles reference
the wheelchair X or Y axis
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Example: Sagittal thigh angle
SAGITTAL THIGH ANGLE
• Sagittal thigh angle = the
degree of rotation of the sagittal
thigh line away from the
horizontal
Horizontal
Sagittal Thigh line
Sagittal thigh angle – Direction of rotation
SAGITTAL THIGH ANGLE
• How to define if thigh is rotated
upward or downward relative to
the zero reference axis?
• Use positive and negative
numbers to indicate direction of
rotation away from reference line
• “Left hand grip rule” defines
positive and negative direction of
rotation away from zero reference
• Clockwise rotations are positive,
counterclockwise rotations are
negative
+ 15 degrees
The Clockwise Rule: Clockwise rotations are positive*
*viewed from
right side
*viewed from front
*viewed from top
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Level I
Level II
Sagittal plane Sagittal Pelvic Angle
Sagittal Trunk Angle
Sagittal Thigh Angle
Sagittal Head Angle
Sagittal Upper Trunk Angle
Sagittal Sternal Angle
Sagittal Abdominal Angle
Sagittal Lower Leg Angle
Sagittal Foot Angle
Frontal plane Frontal Pelvic Angle
Frontal Sternal Angle
Frontal Trunk Angle
Frontal Head Angle
Frontal Lower Leg Angle
Frontal Foot Angle
Transverse plane Transverse Pelvic Angle
Transverse Trunk Angle
Transverse Head Angle
Transverse Thigh Angle
Transverse Foot Angle
Sagittal absolute body segment angles • Sagittal body segment angles measure the orientation of the body segment in the
sagittal plane with respect to either the horizontal or vertical
The angle of the trunk with
respect to the vertical, viewed
from the side
The angle of the pelvis with
respect to the horizontal,
viewed from the side
The angle of the thigh with
respect to the horizontal,
viewed from the side
Frontal absolute body segment angles
• Frontal body segment angles measure the orientation of the body segment in the
frontal plane with respect to either the horizontal or vertical
The angle of the sternum with
respect to the vertical, viewed
from the front
The angle of the pelvis with
respect to the horizontal,
viewed from the front
FRONTAL TRUNK ANGLE
The angle of the whole trunk
with respect to the vertical,
viewed from the front
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Transverse absolute body segment angles
• Transverse body segment angles measure the orientation of the body segment in the
transverse plane with respect to either the wheelchair X or Y axis
The angle of the trunk with
respect to the wheelchair,
viewed from the side
The angle of the pelvis with
respect to the wheelchair,
viewed from the side The angle of the thigh with respect to
the wheelchair, viewed from the top
TRANSVERSE THIGH ANGLE
Examples of Absolute Support Surface Angles
Support name Level 1 Measures Level 2 Measures
Seat Seat sagittal angle Seat frontal angle
Seat transverse angle
Foot support
Foot support sagittal angle Foot support frontal angle
Foot support transverse angle
Arm support
Arm support sagittal angle
Arm support frontal angle
Arm support transverse angle
Back support
Back support sagittal angle Back support frontal angle
Back support transverse angle
Head support Head support sagittal angle Head support frontal angle
Head support transverse angle
Lower leg support
Lower leg support sagittal angle Lower leg support frontal angle
Lower leg support transverse angle
Lateral trunk support Lateral trunk support frontal angle
Lateral trunk support sagittal angle
Lateral trunk support transverse angle
Lateral knee support Lateral knee support transverse angle
Lateral knee support sagittal angle
Lateral knee support frontal angle
Sagittal absolute support surface angles
• Sagittal support surface angles measure the orientation of a support surface in the
sagittal plane with respect to either the horizontal or vertical
The angle of the back support
with respect to the vertical,
viewed from the side
The angle of the seat with
respect to the horizontal,
viewed from the side
The angle of the arm support
with respect to the horizontal,
viewed from the side
Measuring Wheelchair Seated Posture and Seating Supports ISS 2013
28 Kelly Waugh, PT, MAPT
Frontal absolute support surface angles
• Frontal support surface angles measure the orientation of a support surface in the
frontal plane with respect to either the horizontal or vertical
The angle of the back support
with respect to the vertical,
viewed from the front
The angle of the head support
with respect to the horizontal,
viewed from the front
The angle of the lateral trunk
support with respect to the
vertical, viewed from the front
Transverse absolute support surface angles
• Transverse support surface angles measure the orientation of a support surface in the
transverse plane with respect to either the wheelchair X or Y axis
The angle of the back support
with respect to the wheelchair
Y axis, viewed from the top
The angle of lateral knee
support with respect to the
wheelchair X axis, viewed
from the top
The angle of the lower leg
support assembly with respect
to the wheelchair Y axis, viewed
from the top
Measuring Wheelchair Seated Posture
and Seating Supports
1. Background
2. Overview of the Clinical Guide
3. Foundational Concepts
4. Angular Measures
5. Linear Measures
6. Tools for Measurement
7. Future
Measuring Wheelchair Seated Posture and Seating Supports ISS 2013
29 Kelly Waugh, PT, MAPT
5 Linear Measures
General comments
Terminology convention
Examples of linear body measures
• Actual vs. effective
Examples of linear support surface measures
• Height vs. length
• General guidelines
• Actual vs. effective
General Comments on Linear Measures
• Guide includes linear dimensions of the body and seating supports. Wheelchair frame dimensions are not defined or included.
• Linear measures of body taken with person in desired seated position and posture. Why?
• Linear measures of the body are used to specify support surface linear dimensions and placement
• It is important to differentiate body and support surface linear measures
• For example, Buttock/thigh depth does not equal seat depth
• Consistent rule for using terms length, width, depth, thickness and height
Terminology Convention for Linear Measures
• Length (A) = linear dimension in direction of Z axis
• Depth (B) = linear dimension in direction of X axis
• Width(C) = linear dimension in direction of Y axis
• Thickness (D) = linear dimension taken perpendicular to the support surface reference plane
• Height = linear dimension in direction of Z axis measured from an external reference point to a point on the body or support
Measuring Wheelchair Seated Posture and Seating Supports ISS 2013
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Examples of linear body measures
Actual vs. Effective Linear Body Dimensions
The term for the linear measure represents the actual dimension of that single
body segment. If it is more clinically relevant to stay ‘orthogonal’ to a reference
axis while taking the measurement, then add the word “effective” to clarify.
Examples of support surface linear measures
Depth measures Width measures Length measures
Depth, width, length and thickness are “size” dimensions
Measuring Wheelchair Seated Posture and Seating Supports ISS 2013
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Examples of support surface linear measures
Height vs. length
Height or Placement measures Length measures
General Guidelines for Linear Support Surface Measures
• Measures are taken on the contact surface side of the support
• Measures are taken parallel to the support surface reference plane at centerline
• Measures are taken in an unloaded state
• Dimensions are straight linear measures, not curved.
Actual vs. Effective Linear Support Surface Dimensions
• Terms for size dimensions as defined represent the actual dimension of the contact
surface side of the support component.
• The word “effective” can be added to any length, depth or width measure to indicate
that the useable contact surface has been either increased or reduced by the location
of a separate, adjacent or attached component.
Measuring Wheelchair Seated Posture and Seating Supports ISS 2013
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STOP! WHY ARE WE DOING THIS?
• When and why would you take these
measures you just learned about?
Clinical application of these measures
When Purpose Measures
Initial clinical assessment To document current set up of
equipment
Support surface relative angles
Support surface linear dimensions
To document current posture as a
baseline
Body segment relative angles
Body segment absolute angles
To set postural goals Body segment relative angles
Body segment absolute angles
For prescription Body linear dimensions
Support surface linear dimensions
Support surface relative angles
At delivery To ensure accurate set up of seating
supports
Support surface relative angles
Support surface linear dimensions
To document outcomes relative to
postural goals
Body segment relative angles
Body segment absolute angles
At follow - up To document intentional or
unintentional change in seating set up
Support surface relative angles
Support surface linear dimensions
To document positive or negative
postural change
Body segment relative angles
Body segment absolute angles
To document change in body size
Body linear dimensions
• Comparing body segment angles to support surface angles helps to
highlight mismatch, which prompts problem solving
• Comparing mat exam findings to current relative angles and linear
dimensions of the seating system helps to determine the source of
postural problems, informs intervention strategy.
Clinical application of these measures
Helps with problem solving during assessment
Measuring Wheelchair Seated Posture and Seating Supports ISS 2013
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Measure person: Body Segment Relative Angles
Measure equipment: Support Surface Relative Angles
Measuring Wheelchair Seated Posture
and Seating Supports
1. Background
2. Overview of the Clinical Guide
3. Foundational Concepts
4. Angular Measures
5. Linear Measures
6. Tools for Measurement
7. Future
6 Tools for measurement
Tools used to measure relative angles
Goniometer
Tools used to measure absolute angles
Inclinometer or “Angle Finder”
Goniometer with a bubble level
Horizon tool
Tools used to measure linear dimensions
Metal tape measure
Calipers or ‘M-L’ sticks
Measuring Wheelchair Seated Posture and Seating Supports ISS 2013
34 Kelly Waugh, PT, MAPT
Measuring Wheelchair Seated Posture
and Seating Supports
1. Background
2. Overview of the Clinical Guide
3. Foundational Concepts
4. Angular Measures
5. Linear Measures
6. Tools for Measurement
7. Future
7 Future
• Guide is posted on Assistive Technology Partners website:
– http://at-partners.org/WheelchairSeating
• Printed, bound version will be available for purchase soon
• Waugh awarded PVA GRANT YEAR TWO 2012-13
– Education and training on the Guide
– Develop a Glossary of Wheelchair Terms and Definitions (like a
dictionary, with up to 450 terms)
• Revision of ISO 16840-1
7 Future
• Continued tool development
Simple inexpensive tools for use in clinical setting
More sophisticated tools for research
• Research
Improved anatomical landmarks
Reliability/validity of measures
Measure outcomes relative to postural change
Measure relationship between body angles and support surface
angles
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THANK YOU!
Questions?