Is knee valgus actually a GOOD thing? New research

Summary

The video script discusses knee valgus during squats, a common technique often considered poor form. However, recent studies suggest it may be biomechanically advantageous, redistributing load to glutes and potentially increasing weight lifted. While it might appear unattractive, knee valgus is not necessarily harmful and could be a natural response for optimal force production. The script challenges the conventional advice to strengthen glutes and stretch adductors, as it might exacerbate the issue. It concludes that for those with good motor control, experiencing knee valgus during heavy lifts could be functional and not a problem needing correction.

Takeaways

• 🧍 Knee valgus, where the knees cave in during squats, is often considered a sign of poor technique but may actually be biomechanically advantageous.
• 💪 Strengthening the glutes to counteract knee valgus might be misguided, as it could shift the load to the glutes more, potentially increasing knee valgus.
• 🏋️‍♂️ The study analyzed individuals who could squat to parallel and at least 1.5 times body weight, focusing on squatting biomechanics with varying knee positions.
• 🔍 Key findings show that knee valgus reduces the demand on hip adductors and increases the demand on glutes, possibly due to changes in muscle length and leverage.
• 🏋️‍♀️ During squats, the primary muscles responsible for hip extension and standing up from the squat are the adductor magnus and gluteus maximus.
• 🦵 The hamstrings, being bi-articular, are mostly inactive during squats as their contraction could interfere with the movement by causing knee flexion.
• 🤔 Knee valgus may be a natural response to redistribute load and forces, especially when a muscle is too weak to perform the movement effectively.
• 🏆 Elite athletes often display significant knee valgus during maximal force movements, suggesting it might be biomechanically optimal for force production.
• 🧐 The common advice to stretch adductors and strengthen glutes may not be effective, as it does not address the root biomechanical advantages of knee valgus.
• 🦴 Research indicates that knee valgus does not necessarily lead to injury, with ACL strain not reaching injury levels and not causing lateral patellar misalignment.
• 🏋️‍♂️‍♀️ Practicing proper squat form without knee valgus is important for motor control, but during heavy lifts, if knee valgus occurs naturally and helps with weightlifting, it may be functional and not a problem.

Q & A

What is knee valgus during squatting?

Knee valgus is a phenomenon where the knees cave in during the upward phase of the squat movement, often considered as poor technique.

Why is knee valgus typically considered a problem in squatting?

It's considered a problem because it was traditionally thought to be due to weak glutes and strong or tight adductors, which could potentially lead to injury.

What did the new study investigate about knee valgus?

The study investigated how knee valgus and the opposite — pushing the knees out — affects the biomechanics of squatting, particularly focusing on muscle demands during the squat.

What was the key finding of the study regarding knee valgus?

The key finding was that knee valgus reduced the demands on the hip adductors and increased the demands on the glutes, which could be biomechanically advantageous.

How does knee valgus affect the muscles involved in squatting?

Knee valgus shifts the load and forces from the adductors to the glutes, especially during the upward phase of the squat, which can help in lifting more weight.

Why are hamstrings considered inactive during squats?

Hamstrings are inactive because they have a bi-articular muscle conflict; contracting would pull into knee flexion, which is counterproductive during squat hip extension.

What role do the adductor magnus and gluteus maximus play in squatting?

The adductor magnus and gluteus maximus are primarily responsible for active hip extension, which is essential for pulling up out of the squat.

Can strengthening glutes have adverse effects according to the study?

Yes, if a person has stronger glutes, their body might be incentivized to go into knee valgus more to load the glutes more, which could potentially make things worse.

Why might knee valgus be common among athletes and weightlifters?

It might be common because most people train their glutes more than their adductors, leading to an overdeveloped ratio of glutes to adductor magnus, which could naturally lead to knee valgus.

What does the research suggest about the safety of knee valgus?

The research suggests that while knee abduction moments may strain the ACL, the strain plateaus at a level insufficient to injure the ligaments, and the amount of hip medial rotation may not cause lateral patellar misalignment.

What is the practical advice given for dealing with knee valgus during squatting?

The advice is to have the motor control to perform perfect squats without knee valgus during sub-maximal movements, but to accept knee valgus during heavy attempts if it helps lift more weight and doesn't cause pain or discomfort.

Why might good exercise technique not always look aesthetically pleasing?

Good exercise technique is about the movement that allows the desired training adaptations, and in the case of knee valgus, it might be a functional and advantageous part of the squat, even if it doesn't look conventionally 'pretty'.

Outlines

00:00

🏋️‍♂️ Biomechanics of Knee Valgus in Squatting

This paragraph discusses the biomechanics of squatting, specifically addressing the issue of knee valgus, where the knees cave in during the upward phase of the squat. Contrary to common belief that this is a sign of poor technique, the paragraph explains that a new study has found knee valgus can actually reduce the demand on the hip adductors and increase the demand on the glutes, which may be biomechanically advantageous. The study involved individuals capable of squatting heavy weights and examined the muscle demands during squats with different knee positions. The findings suggest that knee valgus can redistribute the load, allowing for heavier squats, and may not be a problem that needs fixing, especially if it occurs involuntarily during heavy lifts and does not cause discomfort.

05:03

🤔 The Functionality and Safety of Knee Valgus

The second paragraph delves into the practical implications and safety concerns of knee valgus during squatting. It acknowledges that while some may advise against knee valgus due to potential knee injuries, research findings are inconclusive and do not definitively link knee valgus with increased injury risk. The paragraph emphasizes that having the motor control to squat without knee valgus is important, especially for non-maximal lifts. However, if an individual with proper motor control experiences knee valgus during heavy attempts and it aids in lifting more weight without causing pain, then it is likely functional and not a problem. The research suggests that knee valgus may be a natural and advantageous movement for some, and the body may even be inclined towards it due to the prevalent training of glutes over adductors. The paragraph concludes by advising not to obsess over knee valgus and to focus on proper exercise technique that stimulates desired training adaptations.

Keywords

💡Knee Valgus

Knee valgus refers to the inward collapse of the knees during the upward phase of a squat, which is often seen as a poor technique. In the video, it is discussed as a common issue that might be wrongly attributed to weak glutes or strong adductors. The script explores the biomechanics of knee valgus and its potential advantages during squatting.

💡Biomechanics

Biomechanics is the study of the mechanical laws relating to the movement or structure of living organisms. The video uses this concept to analyze how different squatting techniques, such as knee valgus, affect muscle demands and movement efficiency. It is central to understanding the study's findings on squatting biomechanics.

💡Glutes

The glutes, or gluteal muscles, are a group of muscles responsible for hip extension and are often implicated in discussions about squatting technique. The script suggests that strengthening the glutes might not always be the solution to knee valgus and could even exacerbate the issue by shifting the load to these muscles.

💡Adductor Magnus

The adductor magnus is one of the muscles responsible for hip adduction, pulling the thigh inward towards the midline of the body. In the context of the video, it is highlighted as a muscle that, when not properly balanced with the glutes, could contribute to knee valgus during squatting.

💡Hip Extension

Hip extension is a movement that involves extending the hip joint, which is a key component of the upward phase of a squat. The video explains that the primary muscles involved in hip extension during a squat are the gluteus maximus and adductor magnus, which propel the body upwards.

💡Hamstrings

Hamstrings are muscles at the back of the thigh that play a role in various movements, including squatting. The script clarifies that during a squat, hamstrings are less active due to a bi-articular muscle conflict, meaning they can't actively extend the hip without flexing the knee.

💡Motor Control

Motor control refers to the brain's ability to control and coordinate movements. The video emphasizes the importance of having motor control to perform squats without knee valgus, especially during sub-maximal lifts, suggesting it is a skill that can be learned and controlled.

💡1RM (One Repetition Maximum)

1RM is the maximum amount of weight that can be lifted for one complete repetition of an exercise. The script mentions that during maximal lifting attempts, knee valgus might occur involuntarily and could be biomechanically advantageous for lifting heavier weights.

💡ACL (Anterior Cruciate Ligament)

The ACL is one of the four major ligaments of the knee that provides stability. The video cites research suggesting that knee valgus might strain the ACL, but the strain does not reach levels that would typically cause injury, indicating that knee valgus may not be as harmful as previously thought.

💡Patellar Misalignment

Patellar misalignment refers to the improper tracking of the kneecap during movement. The script discusses research findings that suggest the degree of hip medial rotation during squat variations, including knee valgus, may not be sufficient to cause lateral patellar misalignment.

💡Exercise Technique

Exercise technique refers to the proper form and execution of physical exercises. The video concludes that good exercise technique is about achieving the desired training adaptations rather than just looking aesthetically pleasing, suggesting that knee valgus could be a part of effective squatting technique for some individuals.

Highlights

Knee valgus, the inward caving of knees during squatting, is often considered poor technique but may have biomechanical advantages.

Strengthening glutes to address knee valgus could be misguided as it might shift the muscle demands from adductors to glutes, potentially worsening the issue.

A new study investigates the biomechanics of squatting with knee valgus versus normal squatting techniques.

Knee valgus reduces the demands on hip adductors and increases the demands on glutes, which may be advantageous for some lifters.

The study examined individuals capable of squatting heavy weights, at least 1 to 1.5 times body weight.

Knee valgus may redistribute muscle load and force, allowing for heavier squats without necessarily causing injury.

Hamstrings are largely inactive during squats due to a bi-articular muscle conflict, serving as stabilizers rather than primary movers.

Adductor Magnus and gluteus maximus are the primary muscles responsible for hip extension during squats.

Knee valgus could be a natural response to biomechanical demands, especially during maximal force movements.

The research suggests that knee valgus may not be harmful to the knees, despite initial assumptions.

The study concludes that knee abduction moments may not be sufficient to injure the ACL.

Hip medial rotation during squat variations may not cause lateral patellar misalignment.

Research on the safety of knee valgus during athletic movements is inconclusive, with no clear evidence of harm.

Elite athletes often display significant knee valgus, suggesting it may be biomechanically optimal for force output.

Practically, one should be able to squat without knee valgus for non-maximal lifts, but it may be functional during heavy attempts.

Knee valgus may not be a problem that needs fixing, but rather a natural and potentially advantageous movement.

Good exercise technique does not necessarily have to look aesthetically pleasing; it should stimulate desired training adaptations.

Transcripts

When you’re squatting.

You may experience that your knees cave in, especially during the upward

phase of the movement as you come out of the hold.

This is called knee valgus.

Knee valgus looks kind of ugly and is generally considered poor technique,

something you should fix, in particular by strengthening your glutes because

your adductors are too strong or too tight they are pulling in your knees.

Your glutes are too weak and not capable of pushing your knees out.

All of this might very well be wrong.

A new study investigated how knee valgus, or the opposite -

pushing the knees way out, affects the biomechanics of squatting.

They looked at people that could squat to parallel

and could squat at least 1 to 1.5 times body weight.

1.5 times for men.

So he basically looked at people squatting with either knee valgus,

the knees coming in, pushing the knees way out,

or squatting normally with their regular technique.

And then they looked at

what are the demands on the particular muscles during the squat.

The key finding was that knee valgus, the knees

caving in, reduced the demands on the hip adductors

that pull the knees in and it increased the demands on the glutes.

The abductors that get to push the knees out.

Now this can happen due to a change in the lengths

of the muscles and due to leverages that these muscles have.

During a squat you want hip extension which essentially pulls you up

out of the squat.

It's like the good morning portion of what you're doing.

That is done by the adductor Magnus and the gluteus maximus primarily.

So the hamstrings are basically inactive

because they have a bi-articular muscle conflict.

Hamstrings are essentially not trained by squats

because if the hamstrings were contracting, they would also pull

you into knee flexion, which kind of pulls you back down into the squat.

So whereas they would like to help at the hip,

they cannot because they would be sabotaging the quads at the knee.

And a muscle can only contract or not contract.

So the hamstrings are essentially just the stabilizers during a squat.

So it's basically the adductor magnus and the abductors, the gluteus maximus

that propel you upwards during a squat that do the active hip extension.

What knee valgus does is it shifts the demands, or in general

the positioning of your knees these two muscles.

And that can be biomechanical advantageous when a muscle is

just a little bit too weak or cannot produce

enough force to get through the movement at that portion.

By shifting the knee position, body essentially redistributes

the load and the forces to make you capable of squatting more weight.

In particular, what knee valgus seems to do

is it shifts the loads and the demands

to the glutes in the portion when you are coming out of the hole.

In that sense knee valgus can actually be functional and advantageous.

And ironically,

the standard advice to strengthen your glutes may thus work adversely

because what knee valgus does is it shifts the demands from the adductor

magnus to the glutes.

So if you have stronger glutes, the body might be extra incentivized

to make you go into knee valgus to load the glutes more.

So the standard advice to strengthen the glutes and to stretch your adductors,

that definitely doesn't work,

but strengthening the glutes in particular might actually make things worse.

And that might actually also explain why we see so much knee valgus,

because most people, they’re training the hell out of their glutes, athletic

weightlifters, power lifters, most women in the gym...

Even men they train their glutes a whole lot more than their adductors.

Most people don't really train their adductors.

The adductor magnus will be trained with your hip extension movements,

but it is only a byproduct of the hip extension training that you're doing,

whereas most people are doing very active glute work in a lot of different ways.

So I think it's fair to say that if anything,

that most people have an overdeveloped ratio of glutes to adductor magnus.

And in that sense, we also know that all of these things that are

purported to fix this, they don't actually work.

Like if strengthening the glutes was the solution,

if it was a case of muscular imbalance or anything like that,

then you wouldn't see it all the time in the top weightlifters, in the top power

lifters, in many athletes...

Elite athletes of all kinds display significant knee values.

And it's particularly the case when you're doing maximal force movements,

which also shows that it's probably biomechanically advantageous.

If elite athletes are doing it, and you cannot train it away,

like the body is almost forcing you do it, that is usually an indication

that is the biomechanically optimal way to perform the movement.

Because if you're telling the body I need to squat this weight

no matter what, then the body will make you move in such a way

as to produce the highest amounts of forces.

So in that sense, this research actually strongly suggests, and I think

anecdote as well strongly suggest that knee valgus is a rather natural

and probably biomechanically advantageous phenomenon.

Now, you might be wondering,

even if it is advantageous for force output, isn't it bad for the knees?

It's great and all that you can maybe lift more weight,

but if it messes up your knees in the process,

of course you still don't want to do it, and you want to fix it

and it is really a problem.

So how safe is knee valgus actually?

The researchers conclude the following: “Although knee abduction moments

may strain the anterior cruciate ligament, the ACL, this strain plateaus

at a level insufficient to injure the ligaments.” Later on

they conclude that “The amount of hip medial rotation in all 3 squat variations

may be normal and not sufficient to cause lateral patellar misalignment.”

Research in general regarding the safety of knee values during squatting,

during drop jumping, during athletic movements is very inconclusive.

For example we have one very large study in particular that I think is notable

because it was done in elite female athletes

and the title essentially sums up the research: “Kiss goodbye to the kissing

knees” “No association between a frontal plane inwards

knee motion and risk of future non-contact ACL injury in elite female

athletes.” research generally at this point is very ambiguous

and does not clearly show an effect of knee valgus, whereas it does

show that it's probably biochemically advantageous for certain people

to shift the demands from the adductors to the glutes

during a portion of the squats

when this is beneficial to squat more weight or do more reps.

To conclude, what does this all mean in practice?

Well, my take is that

you should be able to squat and I teach all my students that they can squat

to parallel without knee valgus, especially if it's a none 1RM attempt.

I think you should have the motor control to adequately push your knees out

and I think most people, when they are squatting,

they are not pushing their knees out enough.

They think of the squat as like kind of falling into a harmonica

and that's not how you squat.

Squatting is a lot more about sitting in between your knees.

Most people can achieve

far greater range of motion that way, with more neutral limbal pelvic alignment.

That said, when you have the motor control necessary to perform

perfect squats in textbook form and you still experience that you're

getting knee valgus during heavy attempts, especially during maximal lifting

and it happens almost involuntarily, like you just cannot help it

and it also helps you lift more weight,

which is usually kind of the same thing, like your body is making you move this way

no matter how you try to move,

because it's simply

the biomechanically optimal way for your body to perform the movement.

If that is the case, you have the motor control not to do it,

at least during sub-maximal movements

and it doesn't cause you any pain or discomfort, then the knee

valgus that you are experiencing is probably actually functional.

It is essentially a good thing, not “a problem” that needs to be fixed.

It may look somewhat ugly, but it is probably not really a problem.

There is no strong evidence that it is unsafe for the knees

and there is some evidence that it might help you lift more weight.

So in that sense I think knee valgus is actually a very functional natural thing.

As I explained in my previous video,

good exercise

technique doesn't have to look pretty, good exercise technique is simply

the movement that allows you to stimulate the desired training

adaptations, and in this case knee valgus can definitely be a part of that.

So don't obsess over your knee valgus.