My daughter is a high school gymnast. She has sprained her right ankle twice now putting her out of competition for a whole season. The physical therapist is helping her with hip strength and balance. What does the hip strength have to do with it?

You probably remember the old song 'Dem bones' with the line "the hip bone's connected to the thigh bone." The entire leg is connected from top to bottom with each segment affecting the one above or below. Experts call this the kinetic chain.

Studies have shown weakness in the hip muscles with ankle injuries. For a long time researchers wondered if this reduced hip strength was what caused the ankle sprain or the other way around -- maybe the ankle injury resulted in muscle weakness around the hip.

Either way rehab specialist such as your physical therapist test, measure, and treat the entire kinetic chain including hip strengthening with athletes coming back from an ankle sprain.

A recent study may have finally answered the cause or effect question. High school athletes from six different sports were tested preseason for two years. Hip strength and standing balance were the main measures.

By comparing hip strength in athletes who sprained their ankles with those who didn't they found that hip weakness was most likely caused by the injury and not a cause of the injury.