1. Stand with your feet wider than shoulder-width apart and the feet flared to your preference. Stand very close to the edge of a sturdy box, bench, chair, step, or stool.
2. Initiate the movement by breaking at the hips and sitting back, keeping the chest up, the knees out so they track over the toes, and the shins perpendicular to the floor. Remember to push through the heels.
3. Pause for a moment while sitting on the box and then rise, making sure to squeeze the glutes to lockout.
Primary: Quadriceps (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius)
Secondary: Gluteus maximus, gluteus medius, gluteus minimus, hamstrings (biceps femoris, semitendinousus, semimembranosus),
Erector spinae (spinalis, longissimus, iliocostalis).