Shoulder injuries most commonly occur to the rotator cuff muscles and tendons, and may occur due to acute or chronic overuse. An alternate source of injury is a fall or a blow to one of the three shoulder bones. When the humerus, clavicle or scapula suffers forceful trauma, it can pull the connective tissue into an unnatural position and damage it.
The Agency for Healthcare Research and Quality notes that bursitis, tendinitis and shoulder separation are the most common attributable shoulder injuries.
Bursitis
Bursitis occurs when the bursa that cushions the shoulder joint suffers stress and becomes inflamed. Overuse from sports injury, household chores or poor posture can spur this painful rotator cuff condition. Overhead reaching or lifting motions are the most common causes, but the Mayo Clinic notes that diabetes, gout, arthritis and thyroid disease also increase risk for bursitis.
Shoulder pain and swelling at the joint capsule, with reduced range of motion develop gradually. Treatment includes immobilizing the shoulder and arm, reducing inflammation, addressing shoulder pain and making lifestyle modifications. According to the Mayo Clinic, a corticosteroid injection and physical therapy may be necessary to heal severe cases.
Tendinitis
Tendinitis affects the tendons that connect the rotator cuff muscles to bone. Injuries to shoulder tendons can occur acutely during overexertion, such as lifting something heavy above shoulder level, or gradually due to repetetive overhead motions, such as pitching a baseball or reaching for a high shelf in the workplace.
The University of Maryland Medical Center reports that people over 40 and athletes have the greatest risk for tendinitis, which is characterized by shoulder pain and inflammation. Pain and weakness during movement require rest and treatment similar to that of bursitis.
Shoulder Separation
Aggravated tendinitis or acute shoulder trauma may cause the rotator cuff ligaments to tear, creating a separation of the collarbone from the shoulder joint. Intense shoulder pain and limited mobility of the joint and arm can develop immediately or gradually. Shoulder injuries involving separation are graded from I to III by severity.
According to the American Orthopaedic Society for Sports Medicine, grade I indicates ligament damage without actual separation, grade II means that ligaments are partially torn, creating minor separation, and grade III indicates a full tear and obvious, complete separation of joint and bone. Treatment includes pain relief and prevention of frozen shoulder through gentle exercise. Severe separations that involve residual tissue damage may require surgical repair.
