Evaluation of shoulder abductors strength in rheumatoid arthritis using a modified sphygmomanometer

Abstract EN

Objective : To quantitatively assess the voluntary power of the shoulder abductor muscles in patients with rheumatoid arthritis (RA) in the clinical neuromuscular examination.

Also, to assess the inter-patient and inter-observer variation in evaluating muscle strength using a modified sphygmomanometer technique.

Methods : 50 patients diagnosed to have RA were subjected to this study.

All of them could hold their right arm in abduction against gravity, had no severe or painful synovitis or evidence of major destruction in that shoulder or elbow joints.

The cuff and bladder of a mercury sphygmomanometer, folded into 4 equal sections, were placed on the lateral lower third of the right arm.

The pressure inside the cuff was raised to a base line of 30 mm Hg, then the patient’s arm was abducted to 45° at the shoulder joint.

The patient was asked to hold that position and pressure was applied on the opposite side by the observer.

The test was performed by 3 observers and 3 measurements were taken for each patient.

Results : Estimates of inter-patient and inter-observer variations showed no statistically significant difference (p > 0.05) on comparing results using the ANOVA test.

Conclusion : The method proved simple, reproducible, portable, safe, unexpensive and can be applied to other muscles.