The only thing you can do to improve a knee injury is to strengthen the muscles around it, or have surgery then strengthen the muscles around it. I have lived with knee problems from a football injury since I was 13 years old. Major surgery, arthritis, taught me that knee injuries are special. Most people will never fully recover from their knee problem because they will not build the habit of strengthening those muscles. I did it using the Isorobic Exerciser. This most requested DVD tell how I did it. Building and maintaining Hamstring/Quadriceps balance has allowed me to defy medical predictions and maintain the cardiovascular endurance of a 5 mile a day runner even though I can run only one day a week. If you have a knee problem consult your physician then try this DVD.