Shoulder pain / Rotator cuff tendinopathy
Article written by Claire Griffin.
The shoulder joint is the most complex joint in the body, compromising stability for mobility. Consequently shoulder pain is very common amongst the sporting population, particularly those involved in overhead sports such as tennis or throwing sports. The rotator cuff is a group of shoulder muscles that are responsible for stabilising the shoulder joint. These muscles all originate from the scapula (shoulder blade) and insert onto the humerus (upper arm bone). The rotator cuff muscles are the supraspinatus, infraspinatus, teres minor and subscapularis (SITS). Commonly the tendons of these muscles become damaged and swollen (in a condition known as a rotator cuff tendinopathy), leading to pain in the shoulder and muscular weakness. Clinical features of a rotator cuff tendinopathy include pain with overhead activities, such as during a serve or a smash in tennis.
The supraspinatus tendon is one of the most frequent of the rotator cuff to cause pain. Its primary function is to abduct the humerus i.e. move the arm outwards from the side, away from the midline of the body. Supraspinatus tendinopathy commonly causes impingement within the joint, demonstrating a painful arc of movement, in which pain is elicited between 70 – 120 degrees of abduction. This may be caused by compression of the swollen tendon by the head of the humerus. Recent research has highlighted that pain from an overloaded or damaged tendon may not be felt for 48 hours after sport, due to the slow-responding nature of tendons, both to pain and overload, and to rehabilitation.
Examination of rotator cuff tendinopathy may reveal tenderness over the tendon, pain on active movement, pain on resisted contraction of the muscle and weakness in the muscle/s. Shoulder instability and muscle imbalance often co-exist with tendinopathies, so it is important that these are recognised during assessment. The presence of myofascial trigger points, which may themselves cause pain, and reduce the range of motion at the joint, should be investigated.
Treatment of rotator cuff tendinopathy should firstly involve treatment of the tendinopathy itself and secondly treatment of the causative factors. The person should avoid aggravating activities i.e. resting from tennis, and not just avoiding overhead activities during the sport! Ice should be applied locally to the tendon or muscle within the first 24 – 48 hours of onset of pain. The shoulder should be assessed by a Chartered Physiotherapist, who will address any underlying soft tissue tightness, shoulder instability, muscle weakness, scapulohumeral rhythm (movement of the humerus with regard to the scapula) or poor technique during training or sport that may be causing or contributing to the dysfunction.