Updated: Dec 11, 2020
Squats are one of the most — if not the most — well-known exercises in the fitness industry.
It’s one of the first movements you learn when starting your fitness journey: straighten your upper body (head neutral, shoulders back, chest high); keep your core stable, feet a little more than shoulder-width apart; hinge your hips into a posterior tilt; bend your legs and sit on an imaginary chair until your thighs are parallel to the floor (or as low as you can go pain-free and without losing form and balance).
As you ascend, drive through with your heels, squeezing the butt (I like to give a little hip extension at the top for an extra “oomph” in the glutes).
As trainers, we look at the frontal, lateral, and posterior views to point out any muscle imbalances and under- or over-activity. This is how we better program individualized workouts for your success.
But have you ever heard the cue, “Keep your knees behind your toes” when performing a squat or lunge? Is this good advice?
This “rule” originated more than 40 years ago, at Duke University in 1978. It claimed that if anyone let their knees travel beyond their toes when squatting, the knee would experience shearing forces. Although true, the rule may not have taken into consideration how the tactic adds pressure on the hips.
“In 2003, University of Memphis research confirmed that knee stress increased by 28% when the knees were allowed to move past the toes while performing a squat. However, hip stress increased nearly 1,000% when forward movement of the knee was restricted.” — Ace Fitness
So, how can we reduce stress on BOTH hips and knees?
Try distributing equal force in both your hips and knees when executing a squat. As you lower your body, you’ll create a healthy hinge effect at the knee. Make sure the distance that the knees move forward is equal to the distance the hips move backward.
As you continue to lower down, your knees might start moving over your toes to adjust your body’s center of mass. THIS is what breaks the ‘Knees Behind the Toes,’ rule and this is OK! If you were to start “correcting” your form by trying to keep the lower limbs vertical, you might feel yourself falling back or experiencing added pressure or pain in your lower back.
So, we’ve debunked the “keep the knees behind the toes” rule. Why do we still hear it from trainers?
As a group instructor, I use this rule when training a large group of people. It is a good general rule when I’m unable to assess each individual and their differing strengths before each class, erring on the side of caution when it comes to knee pain.
However, as a one-on-one or small group (up to three people) trainer, it is easier to coach each person’s squat and lunge form. In these situations, I am able to identify muscle imbalances and pinpoint the best way to lengthen and strengthen those inhibited muscles.
Keeping your knees behind your toes or letting the knees come forward — both cues depend on your center of mass, length of limbs, and pain or pressure in your hip complex, back, and knees.
Keep this in mind next time you perform those squats!
Is It Ever Okay for Your Knees to Extend beyond Your Toes While Doing Squats or Lunges? — Fabio Comana, Ace Fitness
Squat Myth – Knees Should Never Go Past Your Toes — Nils Oudhuis, Trust Me Physiotherapy