HOW: Stand behind the box/step. Place the leg you want to perform the exercise with on the box/step, step up and balance on that leg. Squeeze the butt muscles in that leg as you balance, and then step back down. The leg never leaves the box/step.
FEEL: You should feel the thigh muscles and the butt muscles working in the leg that is on the box/step.
COMPENSATION: Avoid letting your knee cave in as you step up and step down. Make sure you have equal weight distribution throughout your whole foot the entire time. Avoid pushing off the ground with your back leg as you are stepping up. Don’t step down to fast – try to control it.