I'm a 16-year old basketball player with lots of knee problems. I've been doing a program of exercises to help prevent an ACL injury. I've been doing a box heel touch exercise without problems. What's the next step in the sequence of exercise?

The box heel touch is an exercise used to improve active control of the knee. The goal is to avoid letting the standing knee collapse inward while stepping down off a 12-inch box. As the athlete stands on the box with one leg, he or she lowers the other leg to touch the heel to the floor and come back up. The supporting leg must hold steady without angling in or out.

Once the athlete can do this exercise using neutral knee alignment there is a next step. Place a foam pad on top of the box. The balance pad decreases the stability of the supporting surface. The athlete must maintain balance while completing this exercise. Be sure and use a mirror to help monitor the position of the knee. Any time the knee collapses inward, correct the position before going on. Different size and density of foam pads can be used to offer more or less of a challenge.