Squatting Myths Part 2 of 3

Here is the second installment about squatting.  I am a firm believer in keeping exercise, functional, but with the ever existent caveat that you should let pain be your guide.  Not the exertion type of pain, but the "ouch, I think my femur is about to burst out of my skin, or there is a knife cutting my flesh" kind of pain.  Enjoy.

Myth #2: Your knees should never go past your toes

This one is about as mythical as you can get, as it’s hard to find much information at all regarding it’s origin. Search online and what you will find are numerous references to one study from 1978 at Duke University which found that keeping the lower leg as vertical as possible reduced shearing forces on the knee. I wasn’t able to find the actual paper and there’s no available explanation I’m aware of as to why those researchers believed the knee was incapable of sustaining those forces, or how they performed their study. Whether this is the actual origin of the myth or not, an obscure study with zero supporting evidence is hardly any basis for providing any legitimate rules about squatting.

There was one study conducted in 2003 that essentially recreated this scenario by having experienced weight lifters squat under two conditions. First they squatted normally, allowing their knees to travel forward past their toes. Then, they repeated the movement while restricting forward movement of the knees beyond the toes. This reduced torque at the knee by about 22%, and it also increased torque at the hips by over 1000%. (What appears to be a disproportionate redistribution of forces can be explained by a change in torso angle.) This shows that you can reduce torque at the knee by preventing them from going past the toes, but it doesn’t prove that this is necessary. Interestingly, it appears that letting the knees travel past the toes was part of the “normal” method of squatting for those experienced lifters, and the prevention of forward movement of the knees was accomplished by artificial means. In either case, the volunteers in the study seemed to be fully capable of handling the load without incident or injury.

This shouldn’t be surprising, because your knees go past your toes all the time when you run, jump, walk, sit down, and stand up. This is made possible in part by the natural dorsiflexion range of motion at the ankle. Furthermore, when your knee is flexed, some tension is removed from the gastrocnemius muscle at the knee joint. This allows the ankle to dorsiflex through a greater range of motion than when the knee is fully extended, and permits movement of the knee over and past the toes. Why, all of a sudden, will your knees get blown out if they go past your toes during a squat? It’s amazing how our bodies work but it’s a shame that some people remain so unaware of its capabilities.

The actual distance your knees will travel is dependent upon which type of squat you’re doing, as well as your body proportions. Are you doing front squats? Your knees are definitely going over your toes, no matter what. If they don’t, you’re doing them wrong. Do you have long femurs? Your knees will go further over your toes than an individual with shorter femurs, regardless of which type of squat you do. Are you doing split squats? In that case, your front knee may not go beyond the toes at all, but your back knee will travel well past the toes on that respective leg. Are you doing a back squat? As long as you push your hips back into the squat appropriately, and stay balanced on your midfoot throughout the movement, it doesn’t matter where your knees end up. Let them travel as far forward as they need to.