The shoulder joint complex actually consists of 4 separate joints which act in a highly coordinated fashion and can be considered the ‘core’ of the upper limb.

Functionally it is useful to think of the upper limb as a crane. The scapula (shoulder blade) can be considered the ‘base’ and for the upper limb to function effectively needs to be held firmly onto the body by muscles collectively known as the ‘scapula stabilisers’ which attach to both the neck and the trunk.

The upper limb (‘the arm of the crane’) connects to the scapula via a ball and socket joint (glenohumeral joint). Unlike the hip joint which has a deep socket, the glenohumeral joint has a relatively shallow socket and is therefore inherently unstable. However this design affords us mobility providing us with diverse movements such as reaching overhead and scratching our back. Stability of this joint is provided by a group of small muscles called the rotator cuff that work constantly to ‘pull’ the ball into the socket wherever our arm is in space thus preventing dislocation. Normal function of these muscles is dependant on normal function of the scapula stabiliser muscles.

Shoulder injuries come in all shapes and sizes however the most common problems relate to either shoulder instability or shoulder impingement.

Instability ranges from subluxation where the ‘ball’ moves momentarily out and then back into the ‘socket’, to dislocation where the ‘ball’ dislocates out of the ‘socket’ and either relocates spontaneously or with intervention from a medical professional.

Impingement put simply is pinching or scuffing of soft tissues (mainly the rotator cuff tendons) under a bony arch that overhangs the socket of the shoulder joint leading to inflammation of these soft tissues.

Other common injuries in the shoulder region include AC (acromioclavicular) joint strain, labral tears, and rotator cuff tears. Pain can often also be referred to the shoulder from the neck and middle back regions.

The underlying causes if most shoulder injuries irrespective of the diagnosis are poor muscular control of the scapula and weakness of important stabilising musculature including the rotator cuff. Effective treatment of this region therefore focuses on using specific exercises to normalise this muscle control and strength, but also includes other treatments such as manual therapy to mobilise joint and soft tissue restrictions.