The term 'itis' means inflammation, and in this case, tendinitis indicates inflammation of a tendon. Tendons attach muscles to bones. The word 'muscle' comes from the Latin word for mouse, meaning a muscle has a body and a tail. The tendon is the 'tail' of a muscle, the part that attaches it to a bone. Other forms of inflammation include bursitis (inflamed bursa sac) and arthritis (inflamed joint surface). Tendinitis is usually due to overuse, such as excessive running, jumping or throwing. Here are a few examples of tendinitis that affect athletes and physically active individuals: