Shoulder Biomechanics

The shoulder complex provides greater freedom of motion than any other joint in the body at the expense of reduced stability. Shoulder joint movements include flexion-extension, abduction-addcuction, circumduction and rotation. They result from a complex interplay between static and dynamic stabilizers that require equilibrium and synchronicity. Shoulder instability is a comon problem in active populations, especially young athletes. It can occur in overhead throwing athletes (chronic overuse injuries) but more commonly occurs in contact athletes (acute thraumatic dislocations). The contact sports most commonly associated with shoulder instability include rugby, football, wrestling and hockey. This chapter analyses the clinical functional anatomy and biomechanics of shoulder structures with some insight regarding their patologic changes associated with shoulder instability in the athlete.