Bad to go deeper than 90* on squats?

[MsBeverlyHills]

It's not just about "below parallel" versus "right at parallel." Frankly, I don't think there's much different in terms of danger/benefit to your knee.

mpc

actually there is. "At parallel (where the thigh is parallel to the floor, higher than the depth of a full squat by about 30 degrees), the compressive forces on the patella (kneecap) are actually at their highest. Decelerating, stopping, and reversing direction at this angle can inspire significant knee pain in even healthy people, whereas full squats present no problem." - Huberti & Hayes, Journal of Bone Joint Surgery, 1984: 715-724

 

[Shepherd4]

actually there is. "At parallel (where the thigh is parallel to the floor, higher than the depth of a full squat by about 30 degrees), the compressive forces on the patella (kneecap) are actually at their highest. Decelerating, stopping, and reversing direction at this angle can inspire significant knee pain in even healthy people, whereas full squats present no problem." - Huberti & Hayes, Journal of Bone Joint Surgery, 1984: 715-724

I think you missed my point (probably bad wording on my part). The question to which I was responding earlier asked about the difference between going "below parallel" versus stopping right at parallel -- not rock bottom vs. parallel. My point in responding was that the inch or two difference between parallel and just below parallel isn't going to make much difference. They're both hard on the knees. Far and away the better method (as your cite confirms) is to toss out any concept, notion or idea of parallel or anything related thereto and squat rock bottom.