"9. Squatting is bad for your knees
The idea that squatting is bad for your knees has a few sources. Data on patellofemoral contact (kneecap against the joint) forces during these movements can show forces in excess of nine times an individual's body weight as the knee flexes through 90 degrees. This is coupled with doctors concluding that squatting is bad from your knees after seeing men come to them in pain from squatting. From the doctorâ??s viewpoint, this is a logical conclusion. If you hear people say they hurt their knees from squatting again and again, squatting must be bad for your knees.
The gap in this logic is that most people without a history of knee pain squat without ever experiencing it. Regarding the patellofemoral contact force data, a number that seems strikingly high doesnâ??t necessarily imply that the body is not built to sustain these forces. Most men that have squatting-related knee pain have poor technique. In an attempt to keep their torso vertical, they drive their knees excessively forward. In a good squat, the angle of the shin matches the angle of the torso. This ensures loading of the posterior hip musculature (glutes and hamstrings) and minimizes the anterior shearing forces across your knee. In people with a history of knee pain, itâ??s best to try to maintain a vertical shin angle throughout the motion."
I agree with most of this but I disagree with the last part, about keeping the shin verticle. I think the problem most people have is a lack of ankle ROM - tight gastroc/soleus doesn't allow the shin to come forward enough, forcing the knees to compensate. So I would probably start by suggesting calf stretches and ankle mobility work.
The author says the angle of the shin should match the angle of the torso.. and that the angle of the shin should be verticle? Wouldn't that mean the angle of the torso should be verticle as well (which is exactly what he explained causes the knee problems)?
Also, I've lately noticed that there seems to be a relationship between the adductors and proper squat technique that I hadn't really appreciated before. I'm working on a theory that tight adductors are what causes the "tail tucking" many people get at the bottom of a squat.