Bursitis and Tendinitis Glossary of words

Acromion. The outer part of the shoulder blade.

Arthroscopic surgery. Repairing the interior of a joint by inserting a microscope-like device and surgical tools through small cuts rather than one, large surgical cut.

Biceps muscle. The muscle in the front of the upper arm.

Bursa. A small sac of tissue located between a bone and other moving structures such as muscles, skin, or tendons. The bursa contains a lubricating fluid that allows these structures to glide smoothly.

Bursitis. Inflammation or irritation of a bursa.

Corticosteroids. Synthetic preparations of cortisol, which is a hormone produced by the body. Corticosteroids block the immune system’s production of substances that trigger allergic and inflammatory responses. These drugs may be injected directly into the inflammation site. Generally, symptoms improve or disappear within several days. Frequent injections into the same site are not recommended.

Epicondylitis. A painful and sometimes disabling swelling of the tissues of the elbow.

Humerus. The upper arm bone.

Impingement syndrome. When the rotator cuff becomes inflamed and thickened, it may get trapped under the acromion, resulting in pain or loss of motion.

Inflammation. The characteristic reaction of tissue to injury or disease. It is marked by four signs: swelling, redness, heat, and pain.

Joint. A junction where two bones meet. Most joints are composed of cartilage, joint space, the fibrous capsule, the synovium, and ligaments.

Muscle. A tissue that has the ability to contract, producing movement or force. There are three types of muscle: striated muscle, which is attached to the skeleton; smooth muscle, which is found in such tissues as the stomach and blood vessels; and cardiac muscle, which forms the walls of the heart. For striated muscle to function at its ideal level, the joint and surrounding structures must all be in good condition.

Patella. A flat triangular bone located at the front of the knee joint. Also called the kneecap.

Quadriceps muscle. The large muscle at the front of the thigh.

Radius. The larger of the two bones in the forearm.

Range of motion. The extent to which a joint can move freely and easily.

Rheumatoid arthritis. An autoimmune inflammatory disease that causes pain, swelling, stiffness, and loss of function in the joints.

Rotator cuff. A set of muscles and tendons that secures the arm to the shoulder blade and permits rotation of the arm.

Tendinitis. Inflammation or irritation of a tendon.

Tendons. Fibrous cords that connect muscle to bone.

NIAMS gratefully acknowledges the assistance of the following individuals in the preparation and review of current and previous versions of this booklet: Kimberly Kimpton, P.T., HealthMark, Denver, CO; Cato Laurencin, M.D., Ph.D., University of Virginia; James Panagis, M.D., M.P.H., and Michael Ward, M.D., NIAMS, NIH, Bethesda, MD; and Joseph Shrader, P.T.C. Ped., CC, NIH, Bethesda, MD.