From my experience, the most common error I see in the Squat, or any movement derived from the squat, is a by-product of a collapsing (valgus) knee. The answer isn’t to get stronger knees. There is no such thing. Knees are made of bones NOT muscles. The confusion I see is that a collapsed knee is not a CAUSE but an EFFECT of something else going wrong.
From my observation with over 1,000 individuals in training (not an exaggeration) is that the knee collapses because of weak glutes AND/OR a lack of awareness of the role and purpose of why pushing the “knees out” is a coaches visual cue that the glutes are actually engaged and assisting in the squat.
Only with the bands, or tactile feedback from a coach pressing your knees inward, and you forcefully pushing them out, can you actually feel your glutes engage (or “fire” as the new personal trainers like to call it). The glutes are a powerful muscle responsible for hip extension which is necessary for lifting anything impressive. There’s no other way to feel your glutes engage when you in the bottom of the Squat otherwise. Honestly, I don’t ever really feel my glutes engage when I squat but I know they are because my knees are pushed out over the foot. So instead we coach “knees out” as a visual cue to help athletes engage the glutes where they otherwise wouldn’t know if they were doing so or not.
The other reason we coach “knees out” is to allow the knee “to track over the toes” (if not over the pinky toe). Basic anatomy shows that the primary function of the knee is to fully open and close. When the knee tracks over the foot, we allow the knee to function as it was created to do. When we allow it to collapse inward, on purpose or by accident, not only do we allow it to bend (that’s a good thing), we allow it to twist (the fancy term is called “torsion”). Under load, that’s a big NO-NO and is the number one cause of MCL injuries, ACL injuries, and lateral ankle sprains in ALL field sports.
So next time coach yells push your knees out. Say thanks, coach. I appreciate you trying to keep me off crutches! 😁