Muscles worked: gluteus, quads, hamstrings,and inner thighs, and calves.
Form: stand with the feet beyond shoulder width apart. The wide stance forces the inner thigh muscles to work harder. The toes should be turned out. Hold the medicine ball(optional) in front of the body or hands on the hips. Squat down until the legs are parallel. A partial movement (e.g. half way down) is okay for those with limited mobility. Be sure to keep the back straight and head up. Exhale as you stand up. Keep your hips tucked under, core activated, and ribs to hips.
Be sure to not allow your knees to extend beyond the toes during the course of the lift. This exercise can be performed with or without weighted resistance.