HOW: Get set-up into a football Heisman position using a wall and a swiss ball between your knee and the wall. While maintaining this position and pressure into the ball against the wall, lift up on your toes with the leg that is on the ground. As you do this, lean into the wall and push into the ball as hard as you can with your other leg. Return to starting position and repeat.
FEEL: You will feel your calf, thigh, and butt muscles working on the leg that is in contact with the ground. You will also feel your hip and butt muscles on the side that is pushing against the ball against the wall.
COMPENSATION: Do not drop the ball, do not lean away from the wall or lean back, try to not let your knee bend on the side that is performing the heel raise.