One of the most common things I continue to hear in the gym is “I thought the knees should not go over the toes.” This thought and belief started in 1978 from a study done that showed that moving the knee forward increases pressure. Now this thought has clearly stuck around for years, ruining many backs and doing more harm than good, as is still causing these issues. Whoever is saying this is misinformed and needs to go back into a biomechanics book.
There is one big issue with the study, they used powerlifters, which in their sport the squat is way different than any other squat performed for longevity or athletic adaptations. And with the high loads they use and technique it makes more sense that the results showed what they did.
So what is the right way to squat?
From this point on in your training career the thought of knees cannot go over toes is done. Erase it from your memory and it's time to re-learn how to squat the right way and actually perform proper squat mechanics.
Turn on your TV or go to a sports game or watch someone run on the side of the road. Guess what the knee has to go over the toes for performance and optimal forward locomotion. If we limit this action in training then we are only diminishing the ability for the body to perform the task at high speeds, it also impedes muscles patterning and firing to be able to perform.
Feeling Pressure as my Knees Go Forward
Yes as the knees go forward there is an increased pressure on the joint, but it should not be painful, if you get discomfort or pain as the knees move forward there is a muscle firing problem. Usually the person will feel it right under the kneecap or below, this is an indication that the quadricep muscle is taking most of the force and the hamstring is not influencing the hip and the knee appropriately or not at all. This is very common when people squat they will have an anterior tip forward hips and this diminishes the hamstrings ability to stabilize the knee, then as they squat the squat takes the force and there it is knee pain.
This is a simple fix, more attention to the hamstrings especially isometrically training them to strengthen the influence on the hips and force absorption. Hamstrings create knee health, they allow the knee to track forward appropriately.
Lower Back Problems
If the knees do not go forward and flex as the hips and ankles flex then we start to create a biomechanical problem. By restricting this the force needs to go elsewhere, so it will go to the hips and lower back, with the knees not flexing the trunk will have to flex more to make up the range of motion and stay upright and not fall over. This leads to compression of the lower back (discs and tissues) and increases the activation of the lower back muscles for stability and to maintain the weight. Overtime using this method will lead to overuse injuries or even worse disc issues.
The old way of sitting the hips back and down is dead, this is not going to help you at all, especially if you are an athlete it can impede performance.
Now this does not only apply to the traditional squat, this is the case for single leg exercises as well, split squats, lunges etc. With these we are teaching flexion at many joints to help out with injury prevention, running mechanics and much more. The ability to control the ranges of motion and be strong in those positions allow the body to move without injuries, that is the end goal.
So why would someone train in a way that is not beneficial at preventing injuries or pain?
Let the knees go over the toes and get strong there.
References
1.Fry, A.C., Smith, J.C., & Schilling, B.K. (2003). Effect of Knee Position on Hip and Knee Torques During the Barbell Squat. Journal of Strength and Conditioning Research, 17, 629–633.
2.McLaughlin, Lardner, Dillman; “Kinetics of the Parallel Squat”