A key factor in changing the way rotator cuff pathology is treated has been the greater understanding of the way the cuff functions. The work of Burkhart (1994) explains how the cuff actually biomechanically functions.
Burkhart hypothesizes that the rotator cuff insertion is structured like a suspension bridge; the anterior and posterior regions are likened to the supports and the superior cuff likened to the center span. The cable subtends the insertions for the supra & infraspinatus tendons and is located at the margin of the avascular zone. It is therefore the most common area of degenerative tears of the cuff.
The dynamic stabilizers of the glenohumeral joint are the rotator cuff muscles, which serve to control the position of the humeral head in the glenoid fossa. The muscles (supraspinatus > infraspinatus, teres minor & subscapularis) counteract the action of the deltoid by preventing the head of the humerus from moving superiorly when the arm is raised. An imbalance between the deltoid and the rotator cuff muscle strength may result in excessive superior movement of the humeral head, causing impingement of subacromial structures (supraspinatus > long head of biceps > infraspinatus).
Impingement syndromes of the rotator cuff can be caused by structural or functional dysfunctions and include congenital variations, developmental or degenerative factors, traumatic factors, superior migration of the humeral head due to instabilities or capsular tightness or contact of the humeral head on the coracoacromial arch due to muscle imbalances of scapular and rotator cuff muscles.
Manual Therapy for Rotator Cuff Injuries:
Manual therapy/physiotherapy treatment of impingement syndromes of the rotator cuff must address hypomobilities, instabilities and/or muscle imbalances at the glenohumeral joint. It is also critical to modify the repetitive strain or the inappropriate mechanics during the stroke or work of the upper extremity. This may require advice from a professional such as an ergonomist to modify the work station or a “golf-pro”, “tennis-pro” to modify the swing and the technique.
If left untreated, impingement syndromes can cause tendonosis and subsequently partial or complete tears. Rotator cuff tendonosis is more common in younger age groups. The history of the onset is usually of overuse or may be associated with a painful incident. Predisposing factors include training error or poor technique, inappropriate load, muscle imbalances, poor posture, instabilities and restrictive process. Tendonosis can progress to a chronic degenerative tear after the age of 40. Traumatic tears of the rotator cuff are usually secondary to a fall or a sudden pull of the shoulder in external rotation.
Surgery Not Always Required:
According to Burkhart, not all rotator cuff tears should be surgically repaired. He feels that as long as the infraspinatus, teres minor and subscapularis tendons are intact, debridement of the rotator cuff ends may be sufficient to alleviate the pain. Arthroscopic subacromial decompression can also be recommended if conservative treatment fails (ie; restore ROM, decrease inflammation, address predisposing factors, and establish proper muscle balance in the scapulohumeral region).
Physiotherapy Has An Important Role:
Physiotherapists have a very important role in rebabilitation of injuries. A concise biomechanical assessment of the upper extremity would address muscle imbalances and joint restrictions which are key factors in causing rotator cuff dysfunctions.