Ball and socket joints also allow flexion and extension. Flexion of the shoulder joint occurs when the humerus (upper arm) moves forwards from the rest of the body, which happens at the end of an ...

Four important synovial joints used in most sporting actions are the elbow and shoulder joints in the arm, and the knee and hip joints in the leg. The elbow and knee joints are both hinge joints.

Each role is vital to proper arm function and can only occur when the anatomy around the shoulder is uncompromised. The presence of bony and soft tissue injury as well as muscle weakness and ...