A tendon is a flexible band of fibrous tissue that connects muscles to bones. Tendinitis is inflammation of a tendon. Tendons transmit the pull of the muscle to the bone to cause movement. They are found throughout the body, including the hands, wrists, elbows, shoulders, hips, knees, ankles, and feet.endinitis is inflammation of a tendon. Tendons transmit the pull of the muscle to the bone to cause movement. They are found throughout the body, including the hands, wrists, elbows, shoulders, hips, knees, ankles, and feet.