Tendinitis is the inflammation of a tendon, a tough rope-like tissue that connects muscle to bone.
Tendinitis usually occurs in individuals in middle or old age because it is often the result of overuse over a long period. Tendinitis can occur in younger individuals from acute overuse.
Tendons that commonly become inflamed include:
Tendinitis is a very common injury, especially among individuals who participate in professional or recreational sports and fitness activities and individuals whose jobs involve physical activity. Achilles tendinitis is believed to occur at a rate of somewhere between 6 and 37 cases per 100,000 people; about four out of five injuries of this kind occur during athletic or fitness activities. Bicipital tendinitis is estimated to occur at a rate of 1.2 injuries per 100,000 population.
Tendinitis occurs much more frequently in men than in women, with some estimates suggesting that it occurs as much as six times more often in men. It is not clear whether this increased occurrence is due to differences in participation in sports and other activities that are likely to cause tendinitis or if it is related to another aspect of gender. Individuals over the age of 30 are at an increased risk of tendinitis, with most injuries occurring in individuals age 40–60.
Athletes are at an increased risk of tendinitis compared to the general population. Sports that require repeated movements are the most likely to lead to tendinitis. These include:
Tendonitis is caused in one of two ways. Sudden onset tendinitis can be caused by a sudden overexertion of the tendon. This type of tendinitis is not as common as progressive tendinitis. Progressive tendinitis is caused over time by repeated movements that stretch the tendon. Both sudden stretching and repeated overuse injure the connection between the tendon and the muscle to which it is attached. The injury is largely mechanical, but when it occurs, the body tries to heal it by initiating an inflammatory reaction. Inflammation increases the blood supply, bringing nutrients to the damaged tissues along with immune system cells to combat infection. The result is swelling, tenderness, pain, heat, and redness if the inflammation is close to the skin.
A diagnosis of tendinitis is made after a medical history is taken, including information about what sports and professional activities the individual commonly engages in. Often, this information can be very suggestive of tendinitis without additional tests being necessary. For example, an elbow problem in an individual who plays many hours of tennis each week is quite likely to be extensor tendinitis (tennis elbow).
Some tendon injuries are superficial and easy to identify through a simple manual examination. These include extensor tendinitis over the outside of the elbow, and Achilles tendinitis just above the heel. Several tendons in the shoulder can be overused or stretched; often the shoulder has more than one injury simultaneously. Tendinitis in the biceps, the infraspinatus, or the supraspinatus tendon may accompany a tear of the shoulder ligaments or an impingement of one bone or another. Careful pressure testing and movement of the parts is often all that is necessary to identify the tendinitis.
Rest, ice, compression, and elevation (R.I.C.E.) is typically the recommended method to treat the acute condition. The best way to apply ice is in a bag with water. The water applies the cold directly to the skin. Chemical ice packs can get too cold and cause frostbite. Compression using an elastic wrap minimizes swelling and bleeding in an acute injury. Splinting may help rest the limb. Pain and anti-inflammatory medications (e.g., aspirin, naproxen, ibuprofen) can help reduce pain and swelling. Sometimes the inflammation lingers and requires additional treatment. Injections of cortisonelike drugs often relieves chronic tendinitis, but should be reserved for resistant cases since cortisone can occasionally cause undesirable side effects.
If tendinitis is persistent and unresponsive to nonsurgical treatment, surgery to remove the afflicted portion of tendon can be performed. Surgery is also done to remove calcium buildup that comes with persistent tendinitis.
Generally, tendinitis heals if the provoking activity is stopped. In some cases, such as when an occupationrelated activity is the cause of the injury, making even minor changes to the way in which the activity is performed can help give the tendinitis time to heal and prevent future problems. If a sports activity is causing the tendinitis, small changes in posture or hold can sometimes be beneficial.
If given enough time, tendons will strengthen to meet the demands placed on them. They grow slowly because of their poor blood supply, so adequate time is required for good conditioning. Occupational and physical therapists can help an individual identify ways to change posture, stance, and hold in order to reduce the risk of recurrence.
See also Achilles tendinosis .
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American College of Sports Medicine, 401 W. Michigan St., Indianapolis, IN, 46202-3233, (317) 637-9200, Fax: (317) 634-7817, http://www.acsm.org .
National Academy of Sports Medicine, 1750 E. Northrop Blvd., Ste. 200, Chandler, AZ, 85286, (818) 595-1200, (800) 460-6276, Fax: (480) 656-3276, http://www.nasm.org .
J. Ricker Polsdorfer, MD
Revised by Tish Davidson, AM