− | The shoulder joint links the humerus and the scapula at the '''glenoid cavity''', which is much smaller than the head of the humerus. While structually it is a [[Joints - Anatomy & Physiology#Types of Joints|'''ball and socket''']] joint, it functions as a [[Joints - Anatomy & Physiology#Types of Joints|'''hinge joint''']] due to extensive muscling around the articulation. The joint capsule is enlarged and extends under the tendon of the biceps, acting as a synovial sheath to protect the tendon. | + | *The joint capsule barely extends past the areas of articulation, except where it continues distally into the intertubercular groove of the humerus. This provides cushioning and synovial support for the bicipital tendon. |