HOW: Face a wall, get set-up with your hands supported on the wall at shoulder height with your elbows straight, and a band around the top of your feet. While standing tall with a slight lean forward, as fast as you can lift one leg up driving your knee forward until your thigh is parallel to the ground. Hold this position, slowly lower down and repeat.
FEEL: You will feel your hip flexor muscles working on the side that you lifted the leg. You will also feel your core muscles working and your opposite hip muscles working to maintain balance and single limb stance stability.
COMPENSATION: Do not round or arch your back when you lift/lower your leg. Try to isolate hip movement during the exercise. See video for tips