The high bar back squat and low bar back squat discussion has caused much controversy in the functional fitness community. The truth is both of these squats have their place. The differences in the two lifts are technical and cause the two to work on slightly different muscle groups. The high bar back squat starts with the bar placed on the highest part of the meaty portion of the back also known as the traps. It is initiated with a slight movement backward of the hips. At this point the hips and shoulder begin to descend at the same rate. This causes this type of squat to work mostly on the muscles of the quads and glutes. Also the hamstrings and lower back are worked out to a lower degree. The low bar squat starts with the bar right beneath the upper traps right around the posterior shoulder. The movement is initiated with a movement of the hips as well. Except when descending the shoulders will begin to move slightly faster than the hips. This will cause the shoulders to move forward. This in turn causes your center of gravity to move forward and more pressure is shifted towards the hamstrings and lower back. So essentially the high bar back squat is more quad dominant whereas the low bar back squat is more posterior chain dominant. Both exercises can be applied in a functional fitness setting the elicit results. It all depends on your goal for the day.