Hello Sir, I m 28 years old guy,3 months ago, I was undergone from left knee arthroscopic surgery and my doctor diagnosed ACL Tear (ACL Functionally incompetent), Leg up & down excercises have been suggested,excercises are being done & from excercise i m relatively feeling better but sometime I feel that my knee is giving away, which also cause pain in my knee. I have visited 3 times to Doctor each in a month and he suggested to continue excercise as my leg muscles are weak, I m trying my best to strenghten my legs muscles but muscles are not developing as it should be uptil now, what should I do to strengthen my muscles as early as possible? Is there any special food for this?