Well, that's actually old school thinking. Nowadays its considered better to go ATG (ass to the grass/ground) because it puts less pressure on the knees. Plus it'll work out more of your legs and lower back. In powerlifting competitions its always ATG (I don't mean literally to the ground, but past 90 degress for sure)
I'm guilty of squating ass to the grass, but not with more than three plates. Yes, I'm getting older I'm getting to the point of HIT training with squats. With 4 plates, I go 90 degrees and visualize sitting down in a chair, all the while looking up. Yes, if you look down, you'll go down. Not a pretty sight with 4 or more plates.:eek:
Doing ass to grass squats will eventually rip your knees and should only be done by young bloods who think they're immortal and don't know any better or competitive lifters who will pay any price to win.
ATG or go home. Please don't be that guy. The majority of gains in hypertrophy and strength are seen past-parallel. The only thing worse than a 6" squatter are those TUT morons or Reaver's shadow-boxers.
The shadow boxers were military guys too. It would have been funny if their SSgt would have caught them doing it. LOL I once saw someone turn an upright bench on its back and prop it up with plates to make a decline bench. Out to sea. In swells.
I've been looking for definitive studies online but haven't found anything. But based on my experience, for any guys who ripped their knees while dancing it wasn't recommend to go below 90 while rehabbing, or subsequently in their dance careers.
ROTL ... actually russian technique is grueling and exacting, and doing the art form on a professional level is competitive as hell (have you ever seen Mikhail Baryshnikov at work?).