We all know the importance of proper form during the big compound lifts, especially squats, but what if our the most basic advice – preventing knees over toes – was incorrect?
You’ve undoubtedly heard warnings to not allow your knees to extend over your toes during flexion, or in the fully flexed or bottom position of squats, lunges, step ups or deadlifts. Well, it’s time to expunge that advice from your weight training repertoire.
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Cherry-picked info
It seems, as is often the case with myths that pervade gyms, the belief that knees extending past toes could result in serious injury came from cherry-picked findings from various studies that looked at human biomechanics during squats.
One such study was conducted by a team of researchers at Duke University led by Tom McLaughlin. The findings, which were published in 1978 in the journal Research Quarterly, determined that the knees experienced less sheering forces when the shin remained in a more vertical position during a squat.
And a 2003 study out of the University of Memphis (Fry et al.), published in the journal Strength and Conditioning Research, showed that knee stress increased by 28% when the knees were allowed to move past the toes during a squat.
Faced with this information, it’s clear why this myth has become so pervasive. However, when you dig deeper you find that there is a bigger picture to consider.
Firstly, a critical fact from the University of Memphis study that is often omitted from this discussion is that hip stress (torque) increased nearly 1,070% when forward movement of the knee was restricted during squats.
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Support natural movement
The truth is, the knee extends over the toes in many natural movement patterns where there is deep knee flexion, including walking up stairs and in the primal squat position, which is an anatomically natural and structurally healthy resting posture still extensively used in many cultures. The knee also extends past the toes during other common activities, such as running and cycling.
You might be inclined to point out that all of these movements are done without the added stress of a loaded barbell, but that argument cuts both ways…
Consider that any unnatural effort to keep your knees behind your toes when you squat or lunge under heavy load is far more likely to cause severe injury, potentially to other more complex joint structures in the lower back and hips, as suggested by the findings of the 2003 Journal of Strength and Conditioning study.
That’s because the knee joint is the simplest joint structure in the lower body – it’s a hinge joint. It moves in relation at what happens at the ankle and hip.
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The right way
Having said all this, the answer to optimal squatting technique doesn’t lie in swinging to the other extreme by working to get your knees out as far over your toes as possible with every rep.
Obviously, avoiding excessive forward movement of the knee during squatting and lunging movements will generally be safer, but don’t fixate on restricting the forward movement of the knees.
In fact, don’t fixate on the knee at all. Rather focus on the hip and ankle joint and proper knee movement should generally take care of itself.
For instance, during squats it is important to initiate the movement with a hip hinge – ‘sitting’ back and down – rather than a knee bend.
Another important form tip, but one related to knee flexion, is to ensure that your knees track over your feet, regardless of how far they extend over. This will ensure that the knee moves in the same direction as the ankle joint. This form cue limits the potential for your knees to collapse inward or outward, which also carries serious injury risk.
You should also focus on keeping an upright posture with a natural curve in the lumber spine, while avoiding a forward lean or anterior pelvic tilt.
Lastly, the ability to squat properly from the start hinges largely on your mobility. Without the requisite hip and ankle mobility your body will find ways to compensate. This is often a far greater cause of injury than the isolated mechanics of knee flexion.
Without adequate mobility (and the skill needed to execute a deep ass-to-grass squat with proper form), the debate around knee position in relation to your feet becomes somewhat moot.
Author: Pedro van Gaalen
When he’s not writing about sport or health and fitness, Pedro is probably out training for his next marathon or ultra-marathon. He’s worked as a fitness professional and as a marketing and comms expert. He now combines his passions in his role as managing editor at Fitness magazine.
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