Squat with knees over or beyond your toes?

Some suggest that your knees should always stay above your toes when squatting to minimize the forces working at your knees. However, they fail to realize that squatting that way impacts your upper body posture and results in significantly higher forces at your trunk and hips.

Introduction

Should your knees stay above your toes at all times when squatting? Or are they allowed to protrude forward?

In this blog post, I'll discuss this aspect of squatting that to this day still causes confusion between gym goers. You'll learn what a 'knees over toes' squat and a standard squat are and how they differ.

Then, we'll talk about why it is (still) believed that your knees should not protrude beyond your toes during squatting. Finally, I'll discuss the problems with knees over toes squatting and show you the difference in force in certain joints when doing knees over toes squatting vs normal squats....backed by science, of course!

But before we discuss all that, let me share my experiences with knees over toes squatting with you.

My experience with knee over toes squats

About 16 years ago, when I was squatting, some guy (who happened to be following a fitness instruction course), about 21 years old, was watching me and yelled (with good intentions): 'Don't let your knees go past your toes!"....all while I was doing a heavy set and going beyond parallel.

At that time, it got me off guard, and while at the deepest position, not knowing better, I adjusted my stance and tried to move my knees back so they were above my knees.

By doing so, my whole posture got completely wrecked: my butt went all the way to my back, the inclination at my hip took an extreme angle, I felt more pressure on my knees, and everything felt all in all very awkward, uncomfortable, unnatural, and downright wrong!

But little did I know... after all...that guy was around my age and following some fitness training course to become a private trainer.

I thought to myself: "He must know what he's talking about, so I better adhere to his advice!". Yet at the same time, while I was still in that deep squat position and after adjusting accordingly to his 'advice,' I remember thinking to myself, "How the HECK is this supposed to feel natural this way?!".

Nonetheless, from that point on, I tried doing squats without my knees going past my toes, and no matter what I did or how I positioned my feet...it never felt natural, and each time, I felt a lot of strain on my spine, hips, as well as my knees.

After about 6 months of trying my best to get accustomed to the knees over toes squatting, I recorded myself with a compact camera so I could analyze my form (at that time, the iPhone 1 just came out, and taking pictures or videos was still done using compact cameras, so imagine the struggles I had with squatting knees over toes to the point that I forced myself to bring a compact camera to the gym just to record myself to see what I was doing wrong).

When reviewing the video, I was shocked at how terrible my form looked, trying to keep my knees over my toes when squatting. My butt was all the way in the back, my upper body was extremely inclined forward (!), and my hips were at a really awkward angle. BUT my knees were over my toes, and my lower leg/shins were vertical...GREAT! /sarcasm.

It was at that point that I realized that, no matter what that guy told me, squatting with knees over toes was terrible for my overall form, and thus, I decided to go back squatting how I did previously: keeping a natural squat stance.

Since then, I've been squatting as I did before that terrible advice of that guy. I've read a lot about squatting form and recorded myself multiple times from many angles while I was squatting... and to this day (I'm now almost 36), squatting feels natural, comfortable and causes no pain or other issues to my joints when I'm doing it in an as natural stance as possible.

So now you know about my experience with squatting knees over toes, let's see what the problem is with this stance, why that guy advised me to keep my knees over my toes, and why it's generally considered bad form.

What is the Knees over Toes Squat?

Before I discuss the issue with knees over toes squatting, let's first define what this type of squat is and what 'normal' squatting is.

Knees over toes squat

In a squat where your knees stay above your toes, your hips are pushed back and lowered toward the ground as you squat down until your thighs are parallel (or beyond parallel, if possible).

The reason your hips are pushed to the back a lot is that your knees' positions are maintained over your toes to keep your shins as upright as possible (preferably perpendicular to the floor, i.e., make a 90 degrees angle with the floor, according to people promoting the 'knees over toes'-squat).

The consequence of the above for your upper body is that your torso will make a considerable inclination forward by rotating around your hips to keep your balance.

Normal squat

With a regular/normal (or, as I prefer to call it, a natural) squat, your knees protrude beyond your toes (but not to an extreme end!).

Your hips are still pushed to the back, but much less than with the 'knees over toes'-squat.

As such, your torso's inclination is much less, and your upper body is much more upright compared. The inclination at your hips is also much less severe than the 'knees over toes'-squat.

Why people believe in knees over toes squats

The idea that your knees should not protrude beyond your toes during squatting comes from the belief that allowing them to do so places too much stress on your knees, leading to injuries in your knee joints.

This idea originated in the 1960s when K.Klein suggested that keeping the knees behind the toes in squatting could prevent large knee joint forces.

As a result, for decades and until this day and age, some people still believe that your knees should not go beyond your toes when squatting above all else.

However, subsequent research and a more nuanced understanding of biomechanics have debunked this 'all or nothing' suggestion.

For most people, as research has shown by Illmeier et al., 2023, allowing your knees to protrude beyond your toes (again, not to extreme levels!) should not cause any problems, and is preferred over severely limiting the forward protrusion of your knees.

Correct squat form

As a matter of fact, and as I have experienced personally, letting your knees go past your toes when squatting is a natural movement pattern, as long as you keep good squat form and posture. This means:

• Maintain a straight back.
• Keep your shoulders retracted.
• Brace your core while squatting.
• Keep your toes slightly pointed outward.
• Keep your knees in line with your toes (i.e., not bending inward or outward from the line your toes make!).

When all of the above is maintained, letting your knees protrude beyond your toes (and again, for the umpteenth time, not too extremely) should cause no problems at all and is the preferred way if you want to squat correctly.

The problem with Knees over Toes squats

The problem when you squat while not letting your knees protrude beyond your toes is that your torso needs to lean forward to keep your balance. At the same time, your hips and butt are pushed to the back.

As you can imagine (and as you'll see in the next section), this places more stress on your hips and lower back compared to a posture where your upper body is more upright, as is the case with regular, i.e., natural, squats wherein your knees slightly protrude beyond your toes.

The more upright your torso is, the less stress there is on your lower back and hips due to a smaller moment arm. That's also the reason that front squats cause less low back pain compared to back squats, at least, for the amateur or inexperienced lifter.

With the above in mind and back to knees over toes squats...what happens when we don't let our knees protrude beyond our toes??? Exactly what's described above: strong forward leaning of your upper body, which places tremendous stress on your lower back and hips, especially if you squat with a heavy load.

How large are these differences in forces on your hips and knees? Let's check these out in the next section!

Knees over toes vs regular squats: forces at knees and hips

So, how much are the forces on your knees when squatting? And what about the forces on your hips?

I researched more scientific literature and found an interesting article examining those variables.

The research by Fry et al., 2003, let 7 recreational lifters (with at least 1 year of barbell squat experience) perform 6 squats: 3 where the knees are restricted to be above the toes, and 3 squats where the knees are allowed to protrude beyond the toes.

At the same time, they analyzed the forces on the knees and the hips.

For the regular squat (where the knees are allowed to protrude beyond the toes), they found a force of 150.1Nm at the knees and about 28.2Nm at the hips.

For the knees over toes squat, the forces at the knees were 117.3Nm vs. 302.7Nm at the hips; both values significantly differed between regular squats and knees over toes squats.

As you can see, although the forces on the knees when doing a knees over toes squat are smaller than when you do regular squats...there is tremendously more force on your hips as a result.

(It should be noted, though, that the values above are from squatting with an unloaded barbell (i.e., no weight plates on each side). Squatting with a loaded barbell can logically imply that the forces exerted on your knees and hips may be much greater than those mentioned in the study.)

In their conclusion, and in line with the suggestions by Illmeier et al., 2003, it is advised to permit the knees to move slightly beyond your toes to optimize the forces at all of your joints.

Conclusion

So, should your knees protrude beyond your toes when squatting, or do your knees have to be straight over your feet?

My answer to this, based on my own experience, on many readings on the past and on the literature mentioned previously in this article, is:

Remember, though, if you have pre-existing knee problems, you might deviate from the above statement and may stick to knees over toes squats for the safety of your knees. In that case, always consult a doctor and physical therapist before doing any squatting type.

Otherwise, pull yourself together and get some confidence (I notice some women who are inexperienced with resistance training still lack the confidence to go to a gym, so here's some quotes to up your confidence!) get up there and do some awesome, natural squats!

What do you think of knees over toes squats?