Tendonitis is an overuse injury that develops slowly in the tendons.
Tiny tears occur to a tendon when it is constantly overworked.
The tendon becomes irritated resulting in swelling, heat, redness, and pain. Sports that involve running and jumping can cause tendonitis in the knee, foot, or the calf. Tendonitis in the knees can also occur from biking. Swimming, swinging a golf club, or pitching a ball can cause tendonitis in the shoulder. Tendonitis may also occur from repeated motion such as typing or using a hammer.