To perform BarBell Squats, position bar on the rack high on back of your shoulders, grasping the barbell out to the sides. Dismount the bar from rack and stand with your feet at a shoulder-wide stance. Bend your knees forward while allowing your hips to bend back behind, keeping your back straight and your knees pointed the same way as your feet. Lower yourself until your thighs are just past parallel to floor. Extend your knees and hips to straighten back up.