The Achilles tendon of the lower extremity is subject to continued trauma with overuse due to excessive pronation (inward rotation of the foot on the leg).

Achilles tendonitis has a characteristic cycle of great stiffness and pain in the morning after walking or jogging. Depending on the severity of injury, pain may be present at rest or after vigorous exercise. There may also be local swelling.

With Achilles tendonitis there is usually abnormal motion of the foot and much inward rolling. This causes pain and muscles and tendons of the Achilles tendon to spasm as it tries to balance the foot. As a result, the tendon becomes inflamed from the torque of the imbalance. Some causative factors may include:

Running on flats instead of mixing the motion with some hills

Wearing shoes that cause the Achilles tendon to overstretch

Using a shoe with too much cushioning and not enough stability

Increasing your mileage log too quickly

Running on softer surfaces rather than hard surfaces

Worn shoes needing to be replaced

Lack of stretching tight muscles from running

The athlete should never attempt to "run through" the injured area.

Dr. Robert F. Weiss, a sports podiatrist, was a member of the Medical Advisory Committee of the 1984 and 1988 Olympic Marathon Trials. Weiss is a veteran of 35 Marathon & has a practice in Darien; affiliated with Stamford Hospital and member of Stamford Health Medical Group-Foot & Ankle. For info visit his Web site at www.stamford

healthmedicalgroup.org, and find a Physician-Dr. Robert F. Weiss.