Advertisement for orthosearch.org.uk
Orthopaedic Proceedings Logo

Receive monthly Table of Contents alerts from Orthopaedic Proceedings

Comprehensive article alerts can be set up and managed through your account settings

View my account settings

Visit Orthopaedic Proceedings at:

Loading...

Loading...

Full Access

THE PREVALENCE OF INAPPROPRIATE MUSCLE SEQUENCING IN RECURRENT SHOULDER INSTABILITY



Abstract

Aim: To demonstrate that inappropriate sequencing of activation of shoulder muscles can cause shoulder instability.

Methods. The records of 933 cases of recurrent shoulder instability referred to a specialist shoulder service between 1993 and 2003 were reviewed. All patients were assessed clinically. Muscle patterning abnormality (Bayley 1986) was identified in 428 patients (46%). Confirmatory functional electromyography was performed in 166 (36%). Inappropriate pectoralis major activation was identified in 73% of anterior instability. In posterior instability, inappropriate activation of latissimus dorsi and anterior deltoid was present in 72% and infra-spinatus was suppressed in 19%. Arthroscopic assessment was performed in 141 (33%), identifying structural lesions of instability in 86 (20%).

All patients diagnosed with muscle patterning disorder received specilalist physical therapy using biofeedback. Symptomatic improvement or stability was achieved in 76% of patients with anterior instability but with no previous surgery, and in 53% of patients with previous surgery. Posterior instability was eliminated in 85% of cases.

Conclusion. Muscle patterning abnormalities contribute to recurrent instability of the shoulder in 46% of cases. The success of physical therapy in these patients is high.

Correspondence should be addressed to BESS c/o BOA, 35-43 Lincoln’s Inn Fields, London WC2A 3PE