These roles include providing synchronous scapular rotation during humeral motion, serving as a stable base for ... Each role is vital to proper arm function and can only occur when the anatomy around ...

This motion is unnatural and highly dynamic, often exceeding the physiological limits of the joint. Owing to overload of various anatomical structures, the shoulder is susceptible to injury. Optimal ...

Abduction – movement away from the midline of the body. This occurs at the hip and shoulder joints during a jumping jack movement. Adduction – movement towards the midline of the body.

Deltoid Abduction of the shoulder (moving the arm outwards and away from the body) Outward arm action in a jumping jack Rotator cuffs A group of stabilising muscles of the shoulder which helps to ...