The shoulder is one of the most complex joints in the human body. In view of this complexity making the correct diagnosis in shoulder disorders normally requires a thorough history and examination by an experienced professional.
The main part of the shoulder is a ball and socket joint (glenohumeral joint). However, the shoulder girdle comprises a complex system of muscles, tendons, ligaments, bones and joints, which all need to interact together in a co-ordinated manner to allow the shoulder to function normally.
Unlike the hip joint where the socket is deep and the joint is naturally stable, the socket of the shoulder joint is shallow which allows the shoulder it’s exceptionally large range of motion. This also makes the joint inherently unstable. The socket (glenoid) of the joint is part of the shoulder blade (scapula) which glides and rotates over the ribs at the back of the chest, allowing the shoulder complex an even greater range of movement. The collar bone or clavicle at the front of the shoulder acts like a strut, supporting the scapula. It attaches to the shoulder blade by a joint called the acromioclavicular joint.
There are a large number of muscles, tendons and ligaments around the shoulder joint all acting together in a complex fashion giving movement, strength and stability. Any one or combination of these soft tissues, bones or joints in and around the shoulder can suffer from disorders such as traumatic injuries or degeneration, producing a wide range of symptoms. Of particular importance are 4 muscles which are wrapped like a sleeve around the arm known as the ‘rotator cuff’. Shoulder symptoms include:-