The shoulder is the most movable joint of the body. It also is one of the most unstable joints. As a result, it is the site of many problems and injuries. The following are some of the most common shoulder injuries:

  • Dislocated shoulder. The shoulder is one of the most frequently dislocated joints. Pulling the shoulder backward or rotating it too far can cause the ball of the upper arm bone (humerus) to pop out of the socket (glenoid). Shoulder instability is a condition in which the shoulder dislocates frequently. Sometimes the ball of the upper arm bone is only partially out of the socket. This is called a partial location or subluxation.

Learn more about dislocated shoulders from the American Academy of Orthopaedic Surgeons.

  • Shoulder separation. This injury involves the acromioclavicular (AC) joint, where the collarbone meets the shoulder blade (scapula). The injury occurs when a fall, blow to the shoulder or other trauma tears the ligaments that hold the AC joint together. The outer end of the collarbone may slip out of place, resulting in shoulder pain – ranging from mild to severe – and possibly a bump on the top of the shoulder.

Learn more about shoulder separation from the American Academy of Orthopaedic Surgeons.

  • Glenoid labrum tear. Also called shoulder joint tear, this is an injury to the cartilage that surrounds the rim of the shoulder socket. This injury often results from repetitive motion or trauma from a fall, pull or blow to the shoulder. Symptoms include pain, loss of strength, decreased range of motion and catching, locking or popping of the shoulder.

Learn more about glenoid labrum tears from the American Academy of Orthopaedic Surgery.

  • Torn rotator cuff. Overuse, aging, a fall or other type of trauma can strain the rotator cuff tendons, which can cause them to become inflamed, leading to a tear. The rotator cuff is a network of muscles and tendons that cover the top of the upper arm bone (humerus) to hold it place and enable the arm to rotate. If you experience a rotator cuff injury you may experience pain over the deltoid muscle at the top and outer side of the shoulder, especially when you raise or extend your arm out from your body. Your shoulder may feel weak and you may hear a click or pop when you try to move your shoulder.

Learn more about rotator cuff tears from the American Academy of Orthopaedic Surgeons.

  • Frozen shoulder. Also called adhesive capsulitis, frozen shoulder is a condition in which the shoulder's movement is severely restricted due to the growth of abnormal bands of tissue (called adhesions) between joint surfaces and a lack of synovial fluid to lubricate the joint. Frozen shoulder may have several different causes, including an injury that forces you to stop using your shoulder due to pain, arthritis or recent surgery.

Learn more about frozen shoulder from the American Academy of Orthopaedic Surgeons.

  • Shoulder fracture. A shoulder fracture is a brake or crack in one of the bones of the shoulder, which usually occurs from a fall or blow. The most commonly fractured areas in the shoulder are the collarbone, or clavicle, and the top of the upper arm bone, or humerus, just below the ball. A shoulder fracture usually causes severe pain, with redness and bruising.

Learn more about shoulder fractures and other shoulder injuries from the American Academy of Orthopaedic Surgeons.

  • Impingement syndrome. This condition is a form of tendinitis in which an inflamed and thickened rotator cuff gets squeezed by or impinged on by the acromion, or edge of the shoulder blade, when the arm is moved. Impingement is one of the most common causes of shoulder pain.

Learn more about impingement syndrome from the American Academy of Orthopaedic Surgeons.

  • Shoulder bursitis. Bursitis is inflammation of bursae (singular: bursa) small, fluid-filled sacs that cushion and lubricate large joints, such as the knees, hips and shoulders. Bursitis in the shoulder can have a number of causes including an injury or underlying form of arthritis or rheumatic disease. The result can be pain, swelling and tenderness in the affected area, particularly with motion.