Dr Zach Long - Squat Biomechanics

Dr. Long explains the importance of the adductor muscles in the squat and their impact on knee valgus in beginners vs. experienced athletes.

Transcript:

Now, one of the squat faults we did talk about earlier was that knee valgus squat fault where the knees come inside of the toes, and I’m going to put a caveat on that when it comes to high level weightlifters or people performing really deep squats. And it comes from this research here by Vigostky and Bryanton, where basically they determined that the adductor magnus produces more than 50% of the net hip extension moment of the squat, which actually becomes even more important when we’re talking about deep squats.

So the adductor magnus actually might be more important than the glutes in the squat, and that’s really important to consider in people performing deep squats because, quite commonly, we’ll see what this olympic weightlifter here, Jared Flemming, does, where as he comes out of the bottom of the squat, you see him actually have his knees come in a little bit. Now, this is an individual that, even though I see this knee valgus fault, he’s an elite olympic lifter, he’s won two national championships I believe, that’s not somebody that I’m going to coach away from this squatting pattern. Because I believe it’s his adductors working really hard and producing that hip extensor moment that’s creating that little bit of knee valgus.

Now, how do I differentiate that from somebody that that is a true fault that we need to move away from? What you’ll see with Jared, if you watch him squat and you watch him just sitting down into the squat, he doesn’t have knee valgus, vs. if you see an immature athlete do this, as they are sitting down into the squat, you’ll see them going to valgus on the way down, and you’ll see them going to valgus on the way up. So they’re staying in valgus the whole time. You’ll also see them maybe sometimes do some really asymmetrical valgus in their knees. You just look at it, and it doesn’t look controlled vs. Jared, to me, when I look at that little bit of knee valgus, it looks controlled to me, I’m not worried about that being something that’s going to harm tissue on him.