8/8/2019 100205HM-SB CRA Poster Final 3

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DESCRIPTION AND VALIDATION OF A SIMPLE CLINICALTEST TO SORT OUT CHRONIC LOW BACK PAIN.

A PILOT STUDYSimon Bergeron¹, O. Maria1, M-J.Morneau², H.A. Ménard1

Division of Rheumatology, McGill University¹, Montréal, andClinique Action Sport Physio, Boucherville, Qc, Canada2.

1.1.A new simple clinical observation has herein been established: lumbar para-spinal muscles normallyA new simple clinical observation has herein been established: lumbar para-spinal muscles normally

relax during early lumbar extension.relax during early lumbar extension.

2.2.A new simple clinical test has been described and validated with excellent intra- and inter-observer A new simple clinical test has been described and validated with excellent intra- and inter-observer 

reproducibility and correlation with surface EMG.reproducibility and correlation with surface EMG.

3.3.The test clearly distinguishes normal = asymptomatic AS = mechanical LBP/OA from early-inflamedThe test clearly distinguishes normal = asymptomatic AS = mechanical LBP/OA from early-inflamed

and late-fused AS patients and can be used to confirm the facet origin of an inflammatory pain pattern.and late-fused AS patients and can be used to confirm the facet origin of an inflammatory pain pattern.

4.4.The test can be restored to normal with appropriate early treatmentThe test can be restored to normal with appropriate early treatment..

Rationale and Objective. Chronic Low back pain (LBP) pain is a difficult clinical problem because its precise

diagnosis is often delayed. We posit that it is possible, using a simple clinical test, to  distinguish the origin of LBP as

posterior (synovitis), anterior (disk-vertebra) or referred. Methods. 1. We describe a clinical test with its intra- and

inter-observer reproducibility. 2. We used it in 28 normal individuals (A), 6 patients with symptomatic Ankylosing

Spondylitis (AS) (B), 10 asymptomatic AS (C) and 21 mechanical LBP (D). 3. We validated it using surface

electromyography (EMG) of lumbar para-vertebral muscles. Statistical significance was set at p<0.05. Results.  

During a standardized lumbar extension of the first 0-50% range of motion (ROM), palpation of the lumbar para-

vertebral muscles detects either relaxation (normal) or no relaxation or a contraction (abnormal). Intra-observer 

reproducibility was 100%. Inter-observer agreement was 95.5% (42/44). Muscles relax in group A, C and D. They do

not in group B. EMG performed by a blinded observer confirms the clinical evaluation in all cases: downward tracings

in group A, C and D and, flat or upward tracings in group B. Comparing the mean group difference in μvolts/sec

between the minimum and maximum stable readings obtained in each patient, we find striking differences between the

active AS group B vs. A, C or D (p<0.001). There are no differences between the normal group A vs. C or D (p=0.06

or 0.9) and, C vs. D (p=0,6).   Conclusions. The clinical test we designed for MSK primary care givers is a reliable,easy to learn and perform, reproducible qualitative appreciation of the state of contraction of the lumbar para-vertebral

muscles during extension of the lumbar spine. In normal individuals, those muscles relax during early extension. If 

they don’t, the test is abnormal and a reason must be found. The facet joints and those muscles sharing common

innervations, we propose that the earliest objective manifestation of AS in the lumbar spine is their reflex contraction in

early extension. Preliminary data suggest that this can normalize with early treatment as a measure of disease activity.

1.1.In normal Group A, observers agree 26/28 times on normality for a 93% reproducibility while in activeIn normal Group A, observers agree 26/28 times on normality for a 93% reproducibility while in active

ASAS

group B, observers agree 10/10 times on abnormality. The EMG confirmed a normal pattern in allgroup B, observers agree 10/10 times on abnormality. The EMG confirmed a normal pattern in all groupgroup

A cases (Fig. 1) and an abnormal pattern in all group B cases (Fig. 2).A cases (Fig. 1) and an abnormal pattern in all group B cases (Fig. 2).2.2.In inactive AS group C, 6/6 clinical tests were negative and all patients had a normal EMG.In inactive AS group C, 6/6 clinical tests were negative and all patients had a normal EMG.

3.3.In mechanical group D, 21/21 clinical tests were normal and all patients had a normal EMG.In mechanical group D, 21/21 clinical tests were normal and all patients had a normal EMG.

4.4.Comparison of the changes in mean +/- SE in electrical activity measured inComparison of the changes in mean +/- SE in electrical activity measured in μμvoltvolt /second during early /second during early

lumbar extension (Fig. 3).lumbar extension (Fig. 3).

▶ Group A (Normal): -18.0± 1.7 vs. B (Active AS): +7.5 ±1.8 (p < 2 x 10Group A (Normal): -18.0± 1.7 vs. B (Active AS): +7.5 ±1.8 (p < 2 x 10 -7-7););

▶ Group A vs. group C (Inactive AS): -15,9 ± 2.0 (p = 0.6);Group A vs. group C (Inactive AS): -15,9 ± 2.0 (p = 0.6);

▶ Group A vs. D (Mechanical): -18.2 ± 1,4 (p = 0.9);Group A vs. D (Mechanical): -18.2 ± 1,4 (p = 0.9);

▶ Group B vs. C: p < 2 x 10Group B vs. C: p < 2 x 10 -3-3;;

▶ Group B vs. D: p < 1 x 10Group B vs. D: p < 1 x 10 -8-8;;

▶ Group C vs. D: p = 0.6Group C vs. D: p = 0.6

ABSTRACT

EMG VALIDATIONA clinically blinded observer applies the surface electrodes on each

side of the spine over the previously palpated muscles. The EMG isrepeated several times during the same controlled early extensionROM. A device (Neurotrac) registers electrical activity in μvolt/sec. at16 readings per sec. A computer equipped with a dedicated softwaregenerates and stores tracings over 25-30 sec. The more reproducibletypical tracing is kept for calculations of minima and maxima.

Fig 3. Voltage Change (Mean And SE) In Lumbar Para-spinal Muscles During Early Extension

     T     T T

T* **

* = Significant difference (P < 0,05)1. THE BASIC PRINCIPLE OF THE MSK EXAM IS FOR THE EXAMINER

TO INCREASE PRESSURE IN A MSK STRUCTURE  BY PERFORMINGPASSIVE OR ACTIVE RANGE OF MOTION OR APPLYING EXTERNALPRESSURE.

2. IF THE STRUCTURE IS ABNORMAL THE PATIENT WILL FEELDISCOMFORT OR PAIN AND THAT WILL PROVOKE A VARIABLE BUT

OBSERVABLE ANTALGIC GUARDING REACTION.

3. IN THE LUMBAR SPINE, EXTENSION AND LATERAL/POSTERIOR-LATERAL FLEXIONS EXPLORE POSTERIOR STRUCTURES.

4. BECAUSE FACET JOINTS AND PARA-SPINAL MUSCLES SHARE THESAME INNERVATION, ROM SOLLICITING POSTERIOR STRUCTURESSHOULD CHANGE THE SPINAL MUSCLE KINOPHYSIOLOGY. 

Patients answer a LBP questionnaire, BASFAI and BASDAI and allow access to their medical files.

THE CLINICAL TEST

During a standardized extension of the lumbar 

spine, the para-vertebral muscles are normally

felt to relax with early extension. The test is

abnormal if relaxation is not felt or if muscles

contract. That is interpreted as a posterior or 

facet joint problem.

STUDY GROUPS

A. normal individuals (28);B. patients with active or advanced AS (10);C. patients with asymptomatic AS (6);D. patients with mechanical LBP (scol iosis,discs, old vertebral Fx or lumbar sprain (21). Starting Position Early Extension

RATIONALE

RESULTS

+

Fig 1. Group A Lumbar Para-Spinal Muscles EMG During Extension (↕)

-

Fig 2. Group B Lumbar Paraspinal Muscles EMG During Extension (↕)

Seconds

     M     i    c 

    r     o     v    o 

      l     t 

     M     i    c 

    r     o     v    o 

      l     t 

Seconds

METHODS

CONCLUSIONS

ACKNOWLEDGEMENTS Wyeth Canada