When the anterior cruciate ligament (ACL) is strained, it becomes weak or "deficient" in holding the knee together. Without good ACL strength, the knee can be easily reinjured. This could happen while you are riding or during other activities.

Exercises on a special training disk retrain the ankle and knee to respond to quick movements. Stopping suddenly or changing directions quickly are examples of these types of movements. Balancing on the board or moving the board in many directions without losing your balance is important. This kind of activity improves the joint's sense of direction and position.

Usually eight weeks of exercises on an exercise disk for 15 minutes each day are recommended. This is based on a series of studies done on athletes with ACL injuries. When you have finished your home program, the therapist can measure your strength and balance. This will help you decide if any further rehabilitation is necessary.