Some coaches say you should never let your knees go over your toes, and others say it’s essential that you do. So, who’s right? And where did this idea that you shouldn’t bend your knees too much come from in the first place?

 

Before social media existed, there was ‘Sports Illustrated’ and the idea that it was dangerous to do Deep Knee Bends was born though a combination of a poor study at a bad time getting too much press.
 

In the 1960’s Professor Karl K. Klein was convinced that deep squatting and allowing the knees to travel forward was a contributing factor for severe knee injuries and damage to the internal and supporting structures of the knee joint. It’s believed that his bias greatly affected the results of his study, in which he “proved” this to be true.

 
As a result, in some circles (including the US Army) it became an absolute doctrine that squatting or lunging too deep was dangerous for your knees, and as we humans like to do, it became exaggerated by some to the point that your knees should NEVER PASS YOUR TOES EVER OR YOU WILL EXPLODE!!!

 

If you’re interested you can read a nice short analysis of Kleins effect on the industry here, and a paper referencing more modern squat research here, but when very smart people start measuring and studying very specific angles and circumstances, using out of context study participants with often fairly poor study practices… where does it leave us normal people?

 

Headlines and dramatic click-baiting articles leave us in fear of certain movements. These few studies on deep squats have left people fearful of ANY kind of forward knee travel, which needs to be completely rectified. Deep knee bends and allowing your knees to go over your toes is NORMAL.

 

Where does your knees go when you walk upstairs?
Forwards

 

If you get up from the floor one leg up first, where does your knee go?
Forwards
 

If you’re walking on a steep hill, where do your knees go?
Forwards.
Over your toes.

It does not make ANY sense to actively limit any joint when it’s a movement that joint is capable of.

 

Never bend your elbow past 90 degrees then, get someone else to feed you. Never bend your lower back, get someone else to put your socks on. Never tilt your head back, get someone else to tell you what the sky looks like…

 

That’s a recipe for weakness.

 

Anecdotally, most people know someone who’s had/got a knee injury seemingly as a result of deep squatting. Is that not enough proof that it’s dangerous?

 

Yet if someone with horrendous hip flexibility, sh*t ankles or terrible posture starts doing ass to grass squats with their knees forwards, sure, over time it may aggravate their knees - but that’s not the squats fault, that person was just not ready yet.

 

Why did my car break? Well, the wheels were on sideways, but I decided to drive it anyway

 

 

Imagine 3 groups of people who all train using deep knee bends & forward travelling knees over the course of a few years:

 
Group One: Experienced athletes with 10+ years’ experience who combine deep squats alongside comprehensive strength & accessory programs

 

Group Two: Complete beginners who only do strength training that include deep squats

 

Group Three: Complete beginners who assess their flexibility & stability and work on it alongside training deep squats

 

Groups One and Three will generally be fine, there will be a couple of random whoopsies but that’s just life.

 
Group Two is extremely common, blind strength training with no awareness of how their bodies move or their limitations, yet the squats get the blame. But can you see the real issue?

 

There was no preparation, no foundation, a complete phase of training was completely missed.

 

I experienced this first hand myself; I had no interest in training when I was younger so when I started, I had awful hip flexibility and terrible balance… and my knees HATED me for it. I ended up needing surgery on one of my knees. I looked like I was doing the right movements, but they were just something I was not ready for.

 

Skip forwards a few years of me actually caring about how my joints should move and my knees feel great, I never have any issues with them. I can kneel for long periods, squat to wherever I like and regularly practice split squats and pistol squats to deep ranges.

 

The fact is, if you take any beginner and make them do something incredibly taxing on the body, especially movements that involved a large or end range of motion (like a deep knee bend) at a level they’re not ready for, the chances of injury are high. That’s not the exercise’s or movement’s fault, that’s the coach’s or individual’s fault.

 

ANY position must be built up gradually over time. Most people understand this in a weight context, you don’t jump straight into a 200kg deadlift on your first session, you’d start with an empty bar and build up over time. Exactly the same principle applies to movement. No movement is inherently dangerous but the larger the range of motion, the longer you need to prepare your body – especially if you’ve had long periods of time avoiding or not doing it.
 
 

The biggest issue I face when working with someone who fears a certain movement is trying to show them how weak it’s made them, ironically leaving them more vulnerable to injury.

 

It can start off with “lunges hurt my knees so I don’t do them”, eventually leading to that person unable to get up off the floor unassisted, or unable to take the stairs because of their bad knees… and the scary thing is, that can happen to any of us.

 

There was a nice study done published in the Journal of Strength and Conditioning Research who compared the effects of knee position during squats (though the study size was only 7 so we’ll still take the results with a pinch of salt!)

 
The conclusion was that, yes, the less the knees travel forwards the less torque, and therefore less stress, is placed on the knee. However, that torque must go somewhere, after all you’re still lifting the same weight.

 

On the participants in the study, they measured an average of ~28% increase in torque on the knees during a barbell squat when their knees were allowed to travel forwards (an amount well within the capabilities of a healthy knee). But when their knees were restricted and did not travel over the toes, the torque in their hips increase by over 10 times, or 1,073%.
 

“Although restricting forward movement of the knees may minimize stress on the knees, it is likely that forces are inappropriately transferred to the hips and low-back region. Thus, appropriate joint loading during this exercise may require the knees to move slightly past the toes”

As with everything in the fitness/movement industry, answers are rarely black and white.

 
The fact that it was such a small study does still leave some unanswered questions: what about different body types? Different femur lengths? Torso lengths? Different levels of ankle dorsiflexion? Hip socket type? If you were able to test everyone in the world those percentages will look very different from person to person! Not to mention factors like skill & experience level. 

 
Your knees SHOULD go over your toes and you SHOULD make it a priority to do so in your mobility so that daily life doesn’t become a struggle, but in terms of squatting, lunging, or building leg strength many techniques and positions can be combined, tweaked, customised to each person and their body. Nothing’s wrong, everyone’s different, and different positions will suit other people more than others.

 

Don’t blindly follow someone else’s technique – especially if it causes you pain. You don’t need to stop a certain exercise; you might just need to adapt it to your body.

 

Ultimately, the best way to avoid knee pain is to build strong knees!

 

The best place to start is the Clockwork Hips Drill, a great exercise for a total beginner as you’re completely in control of the angles and range of motion:

youtubeid=EaxJ1NRNfnY

 

After that, Front Foot Elevated Split Squats are great to start building strength and increasing that load tolerance. If you can do these in sets of 10 with weight on both legs, then trust me, stairs won’t be a problem:

youtubeid=kp6Kg6F5pVo

 

Lastly, if you’re confident with the controlled stuff we can stop being so precious about perfect movement!  Life is ugly, if you’re crawling around the floor, chasing something, or running away from something you’re going to end up in ugly looking positions!

 

It’s one of the reasons I love the clockwork concept, by spending time with more movement variety you lessen the likelihood of being caught off guard in a position you haven’t been in before.

 

The Clockwork Squat Drill is a really nice example of this:

youtubeid=KUrhD31RdN8

 

In conclusion, don’t let a seriously restricted study from 60 years ago influence how you are moving. Your body is capable of moving in many incredible ways and everything is just practice!

 

Find the right starting point for YOU and over time you’ll be stronger and more confident and just be able to do the things you love to do without fear!
 

No, you don’t need to do ass to grass heavy deep squats, but that doesn’t mean you should avoid that range of motion either. Include variety in your day and in your training, do some restricted stuff and some deeper stuff, weighed or unweighted, just don’t get scared of something your body is able to do!

 

When you move joints through their full range of motion regularly, you will improve how the supporting muscles function which gives you more wiggle room for any activity.