DEAR DR. DONOHUE: I took up running this past year. In the past few weeks, I have had pain on the fronts of my lower legs. My wife says it is shin splints. What are they, and how do I get rid of them? – J.P.

ANSWER: Shin splints is a diagnosis that merits a retirement. It encompasses a variety of different conditions.

The tibia is the larger lower leg bone. Stress fractures of that bone can cause the pain you describe. Stress fractures are tiny breaks in the bone. They come from overuse, such as when runners increase either the distance they run or their running speed. Running on hard surfaces such as concrete can bring on stress fractures. So can excessive pronation. Pronation is the natural inward turn of the foot when it strikes the ground. Overpronation stresses leg muscles and the tibia. If your shoes are more worn on the big-toe side than the little-toe side, you are pronating to the extreme. A new pair of shoes and a shoe insert can minimize pronation.

Compartmental syndrome is another condition that causes pain in the shin splints area. Leg muscles, leg nerves and blood vessels are encased in a sheath of tough tissue, sort of like a sausage. If the muscles become swollen from too much running, they compress the blood vessels and nerves.

Inflammation of the lower leg bone covering – periostitis – leads to pain in the front of the lower leg. It too is a consequence of too much work with too little rest.

For all of these conditions, rest is mandatory for about four weeks. Walking can be your guide for resumption of running. When you can walk without pain, you can begin to run, but do so at a reduced intensity. Moist heat applied for 15 minutes three or four times a day speeds healing.

If the pain does not go away or if it comes back, stop all running and walk to your doctor.

DEAR DR. DONOHUE: While playing soccer with my son, I got a sudden pain in my calf. It felt like I got hit with a stone. I can’t run, because the pain starts, and it hurts a bit when I walk. What could have happened? – L.B.

ANSWER: Your description fits the diagnosis of tennis leg. It’s a tear in the calf muscle. Tennis is a game where people must initiate quick starts countless times. That involves a strenuous push-off to propel the runner forward, and the muscle that accomplishes the deed is the calf muscle. It can take only so many push-offs until it gives way. Tennis is not the only sport where rapid starts are important. Basketball and soccer demand the same kind of muscle action.

It’s too late for you to benefit from icing the area for 15 minutes three times a day. That lessens the initial swelling and bleeding that are consequences of a muscle tear. Icing is done for the first two or three days.

Now you are at a stage when moist heat is the therapy needed. It facilitates the absorption of blood, and it lessens the swelling and pain. The heat applications are done three times a day for 15 minutes, just like the ice.

In approximately three weeks, you should be walking without pain. In six weeks, if you are pain-free, you can resume athletic activity. If the calf begins to hurt again, a medical consultation is needed.

DEAR DR. DONOHUE: I am 76, and each morning I swim the breast stroke for 65 minutes. I would like to know how many calories I am burning. – R.H.

ANSWER: I have to give you this by body weight. If a person weights 120 pounds, that person burns 9 calories a minute in doing the breast stroke; 150 pounds, 11 calories a minute; 175 pounds, 13 calories a minute. The numbers surprise me. No wonder you never see an overweight swimmer.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.