|History: The patient is a 56 year old maintenance administrator. During an episode of snow shoveling, he developed acute shoulder pain. The shoulder was left untreated. After several months, the patient noticed he was developing a frozen shoulder. He was referred to physical therapy for 8 weeks without success. He was then referred to an Orthopaedic Surgeon who diagnosed a Left Shoulder Adhesive Capsulitis. He performed manipulation under general anesthesia and was able to obtain a full range. It was felt that the motion limitation was primarily due to mechanical and muscle imbalance and not contracted soft tissues. Biomechanical Assessment was ordered.|
Study: Kinematic analysis was performed for the right and left shoulders in flexion/extension, abduction/adduction, and rotation. Dynamic surface EMG was collected simultaneously from the Anterior Deltoid and Trapezius, bilaterally. Results were evaluated for fluidity of the displacement and velocity, and quantitative EMG.
Discussion: The subject exhibited consistent and reproducible kinematic results indicating range of motion end-point dysfunction for flexion, abduction and external rotation. Coefficient of variability was 7%, assuring repeatability of results. There was an indication of discomfort at neutral during both flexion and abduction [Graph I - framed curves]. Graph II is included for comparison with the affected side.
Electromyography Analysis indicated an anterior vs. posterior muscle imbalance for the left shoulder muscle groups. Of particular note is the severe under-utilization of the anterior deltoid muscle and the hyperactivity of the trapezius muscle for all dynamic range of motion activities [Graph III].
Impression: Test data results support mechanical dysfunction of the left shoulder. Velocity and displacement patterns for the active compression phase of shoulder movement did not support the presence of adhesions. The minor disruption of fluidity in velocity and displacement curves at neutral flexion/abduction suggested bicipital tendinitis.
Outcome: Treatment was adjusted according to the test results. Emphasis was placed on pendulum/ Codman, and PNF contract/relax exercises. The patient responded positively and regained almost full shoulder motion.