Topic Overview

Minor shoulder problems, such as sore muscles and aches and pains, are common. Shoulder problems develop from everyday wear and tear, overuse, or an injury. They can also be caused by the natural process of aging.

Your shoulder joints move every time you move your arms. To better understand shoulder problems and injuries, you may want to review the anatomy and function of the shoulder. The shoulder is a ball-and-socket joint with three main bones: the upper arm bone (humerus), collarbone (clavicle), and shoulder blade (scapula). These bones are held together by muscles, tendons, and ligaments. The shoulder joint has the greatest range of motion of any joint in the body. Because of this mobility, the shoulder is more likely to be injured or cause problems. The acromioclavicular (AC) joint, which lies over the top of the shoulder, is also easily injured.

Shoulder problems can be minor or serious. Symptoms may include pain, swelling, numbness, tingling, weakness, changes in temperature or color, or changes in your range of motion. Shoulder injuries most commonly occur during sports activities, work-related tasks, projects around the home, or falls. Home treatment often can help relieve minor aches and pains.

Sudden (acute) injury

Injuries are the most common cause of shoulder pain.

A sudden (acute) injury may occur from a fall on an outstretched arm, a direct blow to the shoulder, or abnormal twisting or bending of the shoulder. Pain may be sudden and severe. Bruising and swelling may develop soon after the injury. If nerves or blood vessels have been injured or pinched during the injury, the shoulder, arm, or hand may feel numb, tingly, weak, or cold, or it may look pale or blue. Acute injuries include:

• Bruises (contusions), which occur when small blood vessels under the skin tear or rupture, often from a twist, bump, or fall. Blood leaks into tissues under the skin and causes a black-and-blue color that often turns purple, red, yellow, and green as the bruise heals.
• Injuries to the tough, ropy fibers (ligaments) that connect bone to bone and help stabilize the shoulder joints (sprains).
• Injuries to the tough, ropy fibers that connect muscle to bone (tendons).
• Pulled muscles (strains).
• Injuries to nerves, such as brachial plexus neuropathy.
• Separation of the shoulder, which occurs when the outer end of the collarbone (clavicle) separates from the end (acromion) of the shoulder blade because of torn ligaments. This injury occurs most often from a blow to a shoulder or a fall onto a shoulder or outstretched hand or arm.
• Damage to one or more of the four tendons that cover the shoulder joint (torn rotator cuff), which may occur from a direct blow to or overstretching of the tendon.
• Broken bones (fractures). A break may occur when a bone is twisted, struck directly, or used to brace against a fall.
• Pulling or pushing bones out of their normal relationship to the other bones that make up the shoulder joint (subluxation or dislocation).

Overuse injuries

You may not recall having a specific injury, especially if symptoms began gradually or during everyday activities. Overuse injuries occur when too much stress is placed on a joint or other tissue, often by overdoing an activity or through repetition of an activity. Overuse injuries include:

• Inflammation of the sac of fluid that cushions and lubricates the joint area between one bone and another bone, a tendon, or the skin (bursitis).
• Inflammation of the tough, ropy fibers that connect muscles to bones (tendinitis). Bicipital tendinitis is an inflammation of one of the tendons that attach the muscle (biceps) on the front of the upper arm bone (humerus) to the shoulder joint. The inflammation usually occurs along the groove (bicipital groove) where the tendon passes over the humerus to attach just above the shoulder joint.
• Muscle strain.
• A frozen shoulder, which is a condition that limits shoulder movement and may follow an injury.
• Overhead arm movements, which may cause tendons to rub or scrape against a part of the shoulder blade called the acromion. This rubbing or scraping may lead to abrasion or inflammation of the rotator cuff tendons (also called impingement syndrome).

Other causes of shoulder symptoms

Overuse and acute injuries are common causes of shoulder symptoms. Less common causes of shoulder symptoms include:

• Muscle tension or poor posture.
• Pain that is coming from somewhere else in your body (referred shoulder pain).
• Breakdown of the cartilage that protects and cushions the shoulder joints (osteoarthritis).
• Calcium buildup in the tendons of the shoulder.
• An irritated or pinched nerve or a herniated disc in the neck.
• Infection in the skin (cellulitis), joint (infectious arthritis), bursa (septic bursitis), or bone (osteomyelitis).
• Invasive cancer that has spread to the bones of the shoulder or spine.
• Abuse. Any shoulder injury (especially a dislocated shoulder) that cannot be explained, does not match the explanation, or occurs repeatedly may be caused by abuse.

Treatment

Treatment for a shoulder injury may include first aid measures, physical therapy, medicine, and, in some cases, surgery. Treatment depends on:

• The location, type, and severity of the injury.
• How long ago the injury occurred.
• Your age, health condition, and activities, such as work, sports, or hobbies.