The shoulder joint (also called the glenohumeral joint) is the most freely mobile joint in the body. This joint is formed from the combination of the humeral head (ball) and the glenoid fossa (socket) on the shoulder blade. It is a ball and socket joint which allows three planes of movement. Motions of the shoulder joint include abduction and adduction, flexion and extension, and rotations as well as any combination of these movements. Due to the large amount of movement available at this joint, it is also considered the least stable.
The motions at the shoulder joint require a fine combination of shoulder mobility and dynamic stability to allow full, smooth movements such as during throwing a ball. Due to this, the shoulder joint relies heavily on support from a group of muscles collectively known as the “rotator cuff complex.” Separately these muscles are the supraspinatus, infraspinatus, teres minor, and subscapularis. These four muscles work together but each also has its own individual role.
Injuries causing damage to the rotator cuff muscles are common. These can be described as feelings of instability, stiffness, weakness, or pain on use. The most common injuries to the rotator cuff include impingement, degeneration, tendonitis, tendinopathy, and tears. Trauma, repetitive strain, muscle imbalances, general increased mobility of the joint, poor posture, and altered shoulder blade alignment are some of the mechanisms that can lead to a shoulder injury. Neck pathologies can also cause problems at the shoulder.
A proper physical examination by a healthcare professional such as a physical therapist is necessary to be able to distinguish the injury site as well as the initial cause of the injury. A proper treatment regime including home exercise program and manual therapy among other treatments will help you to restore shoulder function to your highest capacity.