We all have limits. Regardless of whether you are involved in lacrosse, track and field, baseball or tennis, it is very easy to overtrain and extend yourself beyond the state of physical excellence.

One of the most common overuse injuries is heel pain. In the younger athlete, the problem is often caused by a condition known as apophysitis of the calcaneus (heel bone) or Sever's Disease. This condition consists of an inflammation of the growth plate under the heel. It is most common in boys and girls between the ages of 10 to 15.

Major causes occur in sports where cleats are worn, which add to the trauma.

The arch-heel syndrome, better known an plantar fasciitis, can hinder mature athletes. This is an inflammation of the band of muscles and tendons that originate in the toes and insert into the heel. If the process continues to become chronic, it can develop into a heel spur. In other cases the pain could be caused by a stress fracture.

In many of these running sports, especially tennis, there may be involvement of the Achilles tendon. That's the tendon that attaches the calf muscle to the back of the heel.

It is most important to know when to stop and rest, or perhaps get treatment. Otherwise, a partial tear or a possible complete rupture may occur. In all sports we run the risk of fatigue. It may play a role in ankle sprains or collisions between players (especially in lacrosse).

There are many injuries that are due to improper foot balance and support when we run. This needs to be corrected.

In order to prevent injuries, one needs to be well conditioned and do stretching and strengthening exercises before and after the event. It is important to know the warning signs. Fatigue, decrease in performance and a sore throat accompanied by muscle and joint stiffness are some of the signs. These are the times when we are all prone to injury.

Learn to know your body's warning signals as you go compete in your respective sport.

Dr. Robert Weiss lives in Westport and has a sports-podiatry practice in Darien. He is a former marathon runner and was a member of the Medical Advisory Committee of the 1984 and the 1988 Olympic Trials.