HOW: Begin the exercise in a forearm plank position. Perform the exercise by bending your knees until just before they touch the ground followed by squeezing your quads to fully straighten your knees, hold that position, then repeat.
FEEL: You will feel your quad muscles working with this exercise along with a calf and hamstring stretch behind your knee. You will also be working your core and shoulder muscles holding the plank
COMPENSATION: Focus on getting your knee fully straight while keeping the rest of your body still in the plank position