What is Rotator Cuff Tendinopathy
Rotator cuff tendinopathy can be defined as a range of pathologies involving one or several of the four rotator cuff muscles, which have become subject to repetitive overloading or friction, causing an accumulation of microtears that fail to heal correctly.
In the above case presentation, the like tissue causing symptoms are the rotator cuff muscles. The coracohumeral and glenohumeral ligaments and the biceps' long-head tendon may also be implicated. The supraspinatus and infraspinatus tendons join to form a single tendon, that with the coracohumeral and glenohumeral ligament form a sheath that stabilises the biceps' long-head. Should an injury occur to any of these structures, the biceps' long-head cannot draw the humeral head into the glenoid fossa. Causing a superior translation of the greater tubercle, the attachment point for the supraspinatus, infraspinatus, and teres minor, which can become impinged on the coracoacromial arch as the arm is elevated, causing friction and resulting in tendinopathies.
The supraspinatus and, to a lesser extent, the infraspinatus function to resist the upward pull of the deltoid on the humeral head when the arm is elevated. Likewise, the subscapularis functions to resist anterior translation on external rotation, and the teres minor compensates for internal rotation produced by the latissimus dorsi on adduction and draws the humeral head posteriorly. Therefore, the instability caused if one of these muscles cannot function correctly, results in improper movement of the humeral head when the arm is elevated, which increases the likelihood of impingements occurring.
The supraspinatus is the most susceptible to tendinopathy when the arm is elevated
overhead due to its proximity to the acromion. Furthermore, the supraspinatus's underside is more avascular, weaker and with repetitive overhead activity, becomes involved in internal impingement. Occurring when the underside repeatedly rubs on the posterosuperior aspect of the labarum, resulting in tendinopathy.
The maintaining factor could affect the presentation because a winged scapular may indicate an axillary nerve palsy with associated trauma to the long-thoracic nerve, causing weakness in the muscles they innervate. The long-thoracic nerve innervates the serratus anterior and functions to keep the scapular close to the rib cage, preventing winging and aligning the glenoid fossa in overhead activates. The axillary nerve innervates the deltoid and teres minor. If the deltoid is unable to contract effectively, the supraspinatus must compensate in the abduction, overloading the tendons.
Furthermore, the excessive internal rotation, caused by a weak teres minor, leads to the articular joint capsule losing tension, causing the rotator cuff to compensate, causing tendon overload.
Additionally, the inability to correctly align the humeral head and rotate externally leads to the greater tubercle impinging on the coracoacromial arch on the elevation of the arm.
Tenondopathy is one of the many dysfunctions of the glenoid humeral joint (shoulder), which can cause discomfort and affect normal daily activities. To discuss your symptoms and treatment options, please contact us on 07901870166. Kind regards Robert @ Optimal Health Clinic