Begin by positioning a barbell at or just below shoulder level in the squat rack. Behind the squat rack, place a tall wooden box or chair. Place yourself underneath the barbell. Make sure the bar is across your upper traps and NOT on your neck.
Place your feet outside of shoulder-width with your toes pointed slightly out. Brace your core and keep your chest up.
Bend at the knees as you drive your hips back. Lower yourself slowly until your butt touches the box. Pause then drive your hips forward to return to the starting position.
Try these other exercises targeting the same primary muscle group: