Your shoulder complex, composed of the clavicle, scapula, and humerus, is an intricately designed combination of four joints, the Glenohumeral (GH) Joint, the Acromioclavicular (AC) Joint and the Sternoclavicular (SC) Joint and a ‘floating joint’, the Scapulothoracic (ST) Joint.

The GH, AC and SC joints link the arm to the skeleton and the ST joint allows for your shoulder blade to glide over the contours of your upper back. All four joints work collectively to achieve normal shoulder girdle movements. Movements of your shoulder girdle represent a complex dynamic relationship between muscle forces, ligament constraints and bony articulations. Thus within the shoulder complex, it is muscular forces which serve as the primary mechanism for securing the shoulder girdle to the back providing a stable base of support for upper limb movements.

The freedom of movement of your shoulder has been developed at the expense of stability, and it is these competing mobility and stability demands, combined with an amazingly intricate design, which makes your shoulder highly susceptible to injury. Now that you can picture the complexity of this amazing ‘joint’ I shall discuss some common shoulder complaints such as Osteoarthritis (OA) of the AC jt, ‘frozen shoulder’ and bursitis in subsequent issue