The next exercise is called ham sets, which
are your hamstrings, which are in the back of the leg. What you’re going to do is bring
that knee up. You’re going to dig your heal into the bed by contracting your hamstring
muscles which you should feel in the back of your thigh. Hold that for 3 seconds and
then relax. Then contract. As you can see with this one, the knee is not moving at all.
All you’re doing is contracting the hamstring muscles.