DEAR DR. DONOHUE: My teenage daughter plays volleyball for her school. She has developed a painful left knee. Her coach says it is jumper’s knee and that she can play if she can stand the pain. Is that wise? – A.B.

ANSWER: No, it’s unwise.

Jumper’s knee is an inflammation of the large tendon that straightens the knee. The cause is repeated trauma to the tendon that comes on landing from a jump. Tiny tears occur in the tendon, and if it is not permitted to heal, the tears can grow larger.

The pain of jumper’s knee is just below the kneecap.

If she hurts only when she is playing volleyball, then she should take a rest for at least two weeks. If the pain is there after other activities like climbing stairs, then she has to curtail her activities even more. Often the pain of jumper’s knee comes on when seated for a long time.

Anti-inflammatory medicines such as Aleve can calm the inflamed tendon if she has no contraindications to taking this sort of medicine.

She can resume her sport when the pain has gone. Then she should warm the knee with a heating pad or moist heat before playing, and she should ice it after playing.

I don’t know about you, but I am not comfortable with accepting the diagnosis of jumper’s knee without a professional opinion. There are just too many conditions that affect the knee to home in on one without a doctor’s examination. Each of those conditions has its own special treatment. She might lose healing time by sticking to a regimen that is intended only for jumper’s knee.

DEAR DR. DONOHUE: My son is in the eighth grade and wants to play sports. He happens to have epilepsy. It is well-controlled, and he hasn’t had a seizure for more than three years. Should we let him play sports? – R.C.

ANSWER: There is no reason why your son should not play sports if his seizures are controlled and if his neurologist gives you the go-ahead. The ranks of professional athletes include many who have a seizure disorder.

He should not engage in unsupervised swimming. If he swims when a lifeguard is present or if other, good swimmers are with him, then he does not have to stay out of the water.

DEAR DR. DONOHUE: I want bigger arms, and I have been exercising by doing arm curls for more than six months. There has been no change in the size of my biceps. What am I doing wrong? – C.C.

ANSWER: For readers, an arm curl is an exercise where the exerciser holds onto a barbell or dumbbells with the elbows straight. The weight, therefore, is at mid-thigh level. The weight is then lifted until it touches the front of the shoulders. The biceps muscle is the one on the front of the upper arm, the one Popeye loves to flex.

If you are doing only arm curls, you need to introduce some variety into the program. Take a trip the library and look in books on weight training. You’ll find a large number of biceps exercises. Each exercise works out different fibers of the biceps so the muscle is completely exercised.

Are you taking a break in between exercise sessions? You should be. Don’t exercise the same muscle without taking a full day’s break between workouts.

While you’re looking at that weight-training book, look up exercises for the triceps muscle – that’s the muscle on the back of the upper arm. Exercising it will add inches to your arm measurement. Furthermore, you need a balanced program – one that exercises both front and back muscles.

DEAR DR. DONOHUE: What happens when the wind is knocked out of you? – P.P.

ANSWER: A blow to the center of the abdomen traumatizes a network of nerves there and leads to a spasm of the diaphragm. A person can’t breathe for a few seconds.

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.