If you need additional support for this exercise ... They also work the muscles and tissues around the knee. Heel slides strengthen the core muscles, which helps to prevent and treat low back ...

Wall sits are a great exercise to build strength in the quadriceps, which support the knee joint. To do a wall sit, stand ...

Bend the knee and slide one heel up towards the bottom as far as ... solid piece of furniture for support. Slowly lift the heels off the floor as far as is comfortable. Pause in this position ...

and bend your other knee, sliding that heel close to your buttocks. Stop when you feel pain, but stay at that angle of knee bending for a second or two before sliding that heel away from your butt.