Plantar fasciitis is an inflammation of a thick, fibrous ligament in the arch of the foot called the plantar fascia. The plantar fascia attaches into the heel bone and fans out toward the ball of the foot, attaching into the base of the toes. If this ligament is stretched excessively it will become inflamed and begin to cause pain. In severe instances the ligament can rupture resulting in immediate severe pain. If the ligament ruptures the pain is so great that the patient can not place weight on the foot. Should this happen, the foot should be elevated and an ice pack applied. An appointment with your foot doctor should be made at your earliest convenience. Sports such as tennis, racket ball, and aerobics can cause extreme tension on the plantar fascia resulting in small tears or rupture of the ligament. However, other less stressful activities can result in tears or rupture of the plantar fascia under the right set of circumstances. (For a more through discussion of the cause of plantar fasciitis see heel pain) One consequence of small tears in the plantar fascia is the formation of firm nodules within the plantar fascia, called fibromas.

Source: Kirk A. Koepsel, D.P.M.