Stand on one end of a resistance band with your affected leg, the leg should be slightly bent.
Hold the other end of the band with two hands near your chest.
Lean forward while extending your other leg backwards.
Return to the starting position in a slow and controlled movement.
Do not turn your knee inwards during this exercise.
If this exercise goes well, you can ask someone to provide extra resistance by trying to pull your knee slightly inwards with an extra elastic band.