View Full Version : Squat depth & knee strain

Dave Young
10-29-2004, 09:24 AM
I also posted this in Injuries but thought I might get some different insight here:

My education led me to believe that the greater the knee angle, the greater the strain on the knee. I have a client with previous knee strain who squats very deeply (way past parallel to the floor), but is looking to squat higher loads. In light of her previous injury, I suggested that she squat slightly less deep, but she tells me that she believes that is harder on her knees. In fact, she says one of the reasons she squats very deeply is because her knees don't hurt as much. This sounds contrary to me. I say squatting slightly less deep would actually be easier on her knees. What's the truth here? Thanks.

D Young

Robert Wolf
10-29-2004, 09:38 AM

I'm not sure if this is the "truth" but it's my perspective on this. If one can achieve a full squat such that the calves and hammies touch some of the turn around energy can be dissipated by structures other than the knee. If one stops short of this the turnaround forces are directed into the knee. this is not an arguement to bounce out of the bottom position, although some do.

To my knowledge, so long as the biomechanics are sound, injury should be a very low probability regardless of loading. I can almost guarantee that the original knee injury was the result of drifting away from sound form.

Just my $0.02

Ryan Atkins
10-29-2004, 09:42 AM
Hi Dave,

I forget exactly what thread it was, but I know other, knowledgeable members (Lincoln or Brain H., maybe?) of the board have attested to the fact that it actually places less stress on the knees to squat deep than it does to simply squat to parallel.

Another demonstration from the certification seminar this month illustrates the point of how encouraging full range of motion (i.e. full depth squatting) is essential for full functionality. Sit down on the floor in a clear area. Now without bending your knee past 90 degrees, stand up. It's not impossible, but one does have to think of some pretty contrived and unnatural motions in order to accomplish it. This simple demonstration made it remarkably clear to me why it's preferable to train in such a manner. It's how were designed to function.

Hope this helps,


Edit - I posted this without seeing Rob's post. Based on my wording, it could be read that I was implying Robb is not knowledgeable. I hope everyone knows I would NEVER think that!!

Brian Hand
10-29-2004, 11:04 AM
Ryan, that might have been me, and I think I have a demonstration that will make a believer out of most people. Load up a weight that you can power clean easily. Power clean it with no more than a quarter squat dip - it will feel fine. Squat clean it with a nice deep squat - again, no problem. Try and clean it and stop at parallel. Note unpleasant feeling in knees. QED.

I think the main problem with going deep is when people let the tension out of the quads and hams, and the calves get crushed into the hams, and the joint opens up. I think it's best to stop when the hams touch the calves, staying tight in the legs. I have to thank Mr. Taft for the keep the legs tight pointer.

Lynne Pitts
10-29-2004, 12:50 PM
Moving to Injuries; deleting cross-posting.

Please don't cross-post; this is a small board and people will see your question.


John Dryden
10-29-2004, 07:46 PM
My 2 cents for whatever its worth - in Asia, just about everybody squats, many times for hours at a time (since Asians generally have longer trunks and shorter limbs, it is a bit easier for them than westerners). So everyone has destroyed their knees by the time they are in their 20s, right?
Wrong - even the elderly are more flexible than a typical westerner.
I saw one research study that claimed that Asians have a 5% greater incidence of knee problems, but I am sure that is not statistically significant.
I would say go all the way down - the flexibility benefits and all-around athleticism gained is worth the marginal (if any) risk.

Dave Young
10-31-2004, 05:26 PM
Perhaps my attempt at being brief resulted in my asking the wrong question. I am not doubting the benefits or safety of deep squats. I have always learned and taught them that way. My question is this:

Is it more likely to damage the knee to perform a nine-tenths (of an already very deep) squat on the occasional lift for the purpose of moving beyond a load/stamina plateau? Key words: Occasional, nine-tenths, and squat (as opposed to cleans or snatches). On this last point, if squats are controlled movements (as I believe they should be) then you are passing through half, parallel, and nine-tenths squats in a loaded state on your way to a full squat anyway, so it's not as if you're avoiding those knee angles when you perform a full-depth squat. Let me know if this is not recommended for reasons that I am still missing. Thanks for your help.

Ryan Atkins
11-01-2004, 07:50 AM
I'm not sure if it would contribute more to injury or not, but I don't think it's necessary, or even optimal, for completing a max lift. Personally, I like to make good use of the stretch reflex at the bottom portion of the lift. Limiting my range to 9/10 of full movement potential would limit its contribution, IMO.

Although we're traveling through the different phases of the squats in a loaded state, we're not trying to reverse the motion at those particular points. I think that's an important distinction, especially when discussing injury potential. For me the tension in the leg builds up gradually the lower I get into the full squat. Although I'm not slamming my hamstrings into my calves on the lifts, there's generally less tension for me at the half and parallel squat phase compared to the bottom.

Keep in mind I don't lift with what I would call impressive (or in some cases, even respectable) poundages, so I could be off base here. I'm also interested in hearing the thoughts of the experts on this issue.


Brian Hand
11-01-2004, 08:38 AM
Dave, even though it's done with the clean rather than the squat, I think the power clean thing above demonstrates that the knee torques are maxed at some point other than the bottom.

As far as the nine-tenths part goes, I am not sure exaclty what it would be nine tenths of (vertical travel? Angular travel about the knee?) but I get the jist of it, you mean a little short of the usual position. Well I think you can definitely work there safely, but you might actually find that is a weaker position at first, not a stronger one, if your client has poor reversing strength in that position. Here the keys would be "reversing strength" and "in that position." By reversing strength I mean the ability to overcome momentum and go from eccentric to concentric, and it is not the same as pure strength in that position.

If you can train this slightly shortened range of motion with heavier weights, it certainly might be helpful. "Partials" usually means reps with much less of the full ROM, but still you'd be doing a partial, getting used to a heavier weight, extra work for some of the stabilizers, etc.