This exercise really emphasizes quadriceps (front of thigh) muscles as well as your lower leg or calf region. Balance on one leg and reach forward with the opposite leg. The "target" you reach for will be determined by your strength and any symptoms you have present. Reach only as far as you can without causing any discomfort in your knee, or allowing your heel to come up off the ground. Your arms can be behind your back (as shown) or by your side - or if you need help with balance, you can rest one hand lightly on a wall or counter top for assistance.This is in essence a single-leg squat and can be done in front of a chair for security.