The hack squat is an exercise which was invented by George Hackenschmidt, an Estonian strongman and professional wrestler of the 20th century, and the lift is often described as a cross between a squat and a dead lift.
These days, there are two lifts described as a hack squat, one which uses the barbell – the old school original one – and one which uses a sliding hack squat machine. I’ll describe each.
Original Barbell Hack Squat
Standing in front of a barbell with your back to it, assume a dead lift position with a double overhand grip on the barbell, with the bar touching the back of your legs. Keeping your arms straight, your spine locked, and facing forward as you would during a dead lift, drive up using the legs, pulling the bar up with you, keeping it in contact with your body as you do so. Once at the top, slowly lower until the bar is back on the ground.
Machine Hack Squat
Position yourself in the machine back first, with your shoulders under the pads, your feet on the platform. Drive up with the legs and release the lock. Bend knees slowly in a controlled manner stopping around what would be parallel in a regular squat, and drive back up.
Hack Squats are a handy exercise for those who struggle to do barbell squats, and are very good for building the Vastus Medialis (tear drop) of the quad.