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