The shoulder region comprises three components: The gleno-humeral joint; the acromio-clavicular joint and the sterno-clavicular joint.
The gleno-humeral joint allows a free range of abduction, flexion and rotation under the control of the scapula-humeral muscles. The other two joints together allow 90 degrees of rotation of the scapula upon the thorax. The shoulder exhibits several affections peculiar to itself notably tears of the musculo-tendinous cuff, the painful arc syndrome and frozen shoulder. The pain referred from an irritative lesion of the brachial plexus often extends from the base of the neck, over the top of the shoulder, and thence into the arm.
Frozen Shoulder (Adhesive capsulitis; periarthritis) – common RSI for computer users
Computer users commonly develop frozen shoulder; also the condition can be aggravated if working in a cold room. Frozen shoulder occurs as a result of prolonged misalignment of the back, shoulder blade and upper arm - puts significant stress on the ligaments and tendons around the shoulder.
Frozen shoulder is a common but ill-understood affection of the gleno-humeral joint, characterised by pain and uniform limitation of all movements but without radiographic change, and with a tendency to slow spontaneous recovery. Generally non-steroidal anti-inflammatory drugs should be prescribed. Occasionally in a severe case, a short course of steroidal drugs may be justified. Short-wave diathermy is also worth a trial.
Stretching for an object can compound problems further by trapping part of the shoulder capsule.
Recurrent Anterior Dislocation of the Shoulder – Traumatic dislocation of the shoulder is liable to cause structural changes in the gleno-humeral joint, which predispose to repeated dislocations. Uncommonly, dislocation may occur repeatedly in a patient with unduly lax ligaments, in the absence of trauma.
Tenosynovitis of long tendon biceps (over use of the arm)
This is characterised by pain and local tenderness in the region of the bicipital groove of the humerus and the long tendon of the biceps. It is generally ascribed to frictional irritation of the tendon within its groove. The complaint is of pain in the front of the shoulder, made worse on repetitive active use of the arm.
Osteoarthritis of the Shoulder
Unlike most other joints, the shoulder is very seldom affected by osteoarthritis. When it is affected there is usually a clear pre-disposing factor, such as previous injury or disease, avascular necrosis of the humeral head, or senility.
Classification of Disorders of the Shoulder Region (Arthritis):
Pyogenic Arthritis, Rheumatoid Arthritis, Tuberculous Arthritis, Osteoarthritis and Frozen Shoulder.
Recurrent dislocation, Complete tear of tendinous cuff, Painful arc syndrome; Rupture of long tendon biceps, Tenosynovitis of long tendon of biceps.
Disorders of the Acromio-Clavicular Joint: Osteoarthritis & Persistent Dislocation or Subluxation. Arcomio-clavicular osteoarthritis is seen much more often than osteoarthritis of the gleno-humeral joint. Pathologically, there are degeneration and attrition of articular cartilage, and spurs of bone (osteophytes) are formed at the joint margins. In severe cases operation is justified; it should take the form of excision of the lateral end of the clavicle, the conoid and trapezoid ligaments being preserved.