There are three basic ways to squat — high bar squats (with the bar on top of the traps), low bar squats (with the bar right below the spine of the scapula), and front squat squats (with the bar on top of the deltoids). The merits of each style have been debated ad nauseam. But which one is safest?
There is no reason for people who are not Olympic weightlifters to do front squats. They leave out the hamstrings and put all of the stress on the knees, which are not particularly robust joints. If something bad happens (a tear, a twist, or a trip), the knees alone cannot come to the rescue. And this does not even factor in the long term effects of continually stressing a weak joint.
The high bar squat places the bar high on the back. To keep the bar over mid foot, lifters must fight hard to maintain a vertical torso. If something unexpected occurs, people tend to fall forward, not backwards. This makes the bar roll up onto the neck. At heavy weights, this could mean serious injury or death.
The low bar squat fixes both problems. The lower bar placement places the stress on the hips, not the knees. It also keeps the weight away from the neck, giving us some wiggle room in the event of a freak accident. This alone is a powerful argument for the variation.