The shoulder is a complex joint because it needs to have a very large range of movement to carry out its many functions. This complexity means that if injury occurs, quite minor problems can escalate into major dysfunction and pain. The glenohumeral joint (shoulder joint) is shallow and is not often afflicted by osteoarthritis.
The shoulder is mainly held together by muscles, the rotator cuff enveloping the joint and the larger muscles such as deltoid and pectoralis major providing power. Its joint capsule is extensive and 'loose' to allow the joint freedom of movement. Like other areas of the body, the shoulder can suffer from ligament and muscle strains, dislocation, fractures, and joint inflammation. The most common injuries involve the muscles and tendons. One injured muscle, due to it's complex relationship with other muscles, can limit ranges of movement disproportinately to the actual injury.
The shoulder is complex and treatment requires careful diagnosis as well as realistic expectations about speed of recovery. The shoulder has muscles which come from the low back (latisimus dorsi), the back of the skull and spine (trapezius) and down into the forearm (biceps) and treatment also needs to take account of the relationship between the shoulder, arm, neck, spine and ribs.
Injuries occuring from trauma or overuse often cause tendon tears or irritation which can give rise to inflammation and muscle spasm. In extreme cases this can lead to frozen shoulder (adhesive capsulitis) where shoulder movement becomes very limited. This combination of pain and spasm is extremely dibilatiting. Recovery time is variable with some people improving relatively quickly over 1-3 months, whilst some may take 6-12 months. Early intervention in shoulder injuries reduces the risk of frozen shoulder occurring. Why some conditions develop further is poorly understood.
Treatment aims to encourage the range of movement, improve muscle tone and circulation; reducing pain and inflammation. Patients are encouraged to stretch and mobilise the shoulder; this is vital in increasing range of movement and starting the healing process. Patience and stoicism are necessary virtues, but a good outcome is generally achieved.