Inflammation of a TENDON. Usually caused by unusual or excessive physical activity, it may also be infective in origin or secondary to a connective-tissue disorder. The pain and inflammation may be treated with NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), immobilisation splinting, and STEROID injections. Repetitive strain injury (RSI), caused by constant use of a keyboard (typewriter, word processor or computer), presents as tendinitis occurring in the hands and arms (see UPPER LIMB DISORDERS).