Problems with motion, strength, and balance occur in up to 20 percent of the patients who have a total knee replacement. The reasons vary and sometimes are never fully understood. In cases where the cause of the problem is clear, the therapist can apply a specific treatment to regain motion.

Aggressive physical therapy (PT) is often needed when problems persist as much as seven months from the surgery. There's not much danger that anything will happen to the implant with hands on PT. Besides stretching the muscles the therapist may also us a technique called joint mobilization to improve motion.

In mobilization one half of the joint is moved or glided along the other side. During stretching or mobilization you may be put in positions with strong pressure applied. This is necessary to avoid a second operation to surgically manipulate the joint.

Don't be afraid to ask the therapist to explain what he or she is doing. Express your concerns so that you can understand your own treatment.