HOW: Get set-up laying on your stomach with your elbows under your shoulders and hips supported on the ground. On the side, you want to perform the exercise, point your toes towards you and start with your knee on the ground. Begin the exercise by squeezing your quads to fully straighten your knee, hold that position, then return to starting position and repeat.
FEEL: You will feel your quad muscles working with this exercise along with a calf and hamstring stretch behind your knee.
COMPENSATION: Focus on getting your knee fully straight while keeping the rest of your body still.