Sit firmly on a chair and lift one knee towards your chest.
Place both hands behind the lower thigh then press your thigh down into your hands (as if you were straightening your leg out).
Press at a comfortable resistance (~20% resistance to start). Make sure your leg does not move and that you relax your head and shoulders.
Hold for 10-20 seconds.
Release and repeat 2-4 times on each leg.
You can also perform this lying.