Lie on your back, with one leg striaight and the other bent up to your chest as far as you are able to. Link your hands together (or place one over the other) over the top of the tibia bone, below the knee joint and knee cap. Firmly press down to glide the tibia bone backwards. Hold for a second or two, then release. Repeat up to 30 times.

There may be some like discomfort or pressure, but do not push into sharp pain.