HOW: Start with your hands against a wall. Push into the wall with your hip, knee, and ankle to assume a triple extension position. This is your starting position. After maintaining this position for the desired amount of time, simply switch legs. Do so by driving the leg you previously had raised into the ground and switching positions.
FEEL: You should feel your hips, knee, and ankle working hard to maintain position.
COMPENSATION: Adjust how far away from the wall you stand to make sure it feels natural.