This exercise is designed to activate your quadriceps muscle and help you regain full active knee extension. After surgery, it is common to be able to get your knee straight passively like when performing a stretch, but difficult to obtain the same degree of knee extension actively when you walk or go up/down stairs. This exercise will help your ability to actively straighten your knee.
Secure a light resistance band around a sturdy object like a pole or table. You only need a very light resistance, heavier is not necessarily better!
Place your affected leg through the band and rest the resistance band above your knee against the back of your thigh. Do not rest the resistance band below your knee against the back of your calf.
Find an appropriate distance away from the anchor where the band will only have when you straighten your knee.
Start with your surgical knee in a bent position with the band on slack