It’s a fairly common misconception (or something you might have noticed people doing) that you need to keep your knees behind your toes when squatting.
It’s also something that isn’t true.
People tend to say this for two reasons; either there’s too much pressure behind the knee-cap or that there are shearing forces at the patellofemoral joint. In this blog we’ll address both of these misconceptions.
In the knee there are three joints; the tibiofemoral joint which is the main one between the top of your shin bone and bottom of the thigh bone. The superior tibio-fibular joint where two bones in the lower-leg meet just below the knee, and the patellofemoral joint where the back of the knee cap articulates with the front of the thigh bone.
It’s the patellofemoral joint that’s relevant here.
As you squat this joint gets compressed, with the knee-cap gliding downwards. So is there too much pressure in the joint as a result?
Research can be conflicting, but the peak force generally seems to be between 50 and 90 degrees knee flexion ( a fully straight leg being 0 degrees) than when you go further into the squat. So if you squat and the knees go in front of the toes, you actually flex the knees more and the pressure will reduce.
What about the shearing forces behind the knee?
Shearing isn’t a good word and something people quite rightly worry about – but in this instance it’s just the type of force dealt with by the joint.
Your joints are designed to withstand these forces for a decent amount of time and regardless of the knee position relative to toes. If anything you could argue that by using a wider range of movement you are spreading the load more evenly, resulting in less “wear and tear” in the long run, although it is a difficult point to show through research and therefore there is no clear evidence on this.
In short the myth that you need to keep knees behind the toes is exactly that – a myth.
That said, as we highlighted in our last blog, squats are an exercise where correct technique is important. If you have any concerns about technique or otherwise, just get in touch with one of the team and we’d be happy to help.