Ever heard to never let your knees go over your toes when squatting? Maybe you've even heard it applied to lunging. Trainers who use this cue say it's meant to help prevent knee injuries by keeping your weight in your heels, but in reality, this advice is a bit misguided.
"When the knees go over the toes, there is a greater amount of force at the knee joint itself," Chris Cooper, CPT for Cooper Coaching, tells LIVESTRONG.com. "Thus, this idea of never letting the knees go over the toes was born otherwise your knees might explode."
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Because allowing your knees to move over, or even past, your toes also puts a greater amount of stress on the patellofemoral area (knee cap), it can lead to knee pain when squatting or lunging, says Michelle Kania, CSCS, a certified sports and conditioning specialist and owner of One Day Better Training.
However, following this cue won't actually solve the deeper issues that are causing your knee pain, Kania says. Squatting or lunging doesn't actually cause knee pain; it's more likely that the issue stems from muscle imbalances or limited ankle mobility.
In fact, if you don't allow your knees to track over your toes, it transfers the dysfunction elsewhere in your body, including your hips and lower back, so it's actually better to allow forward knee movement during squats and lunges if it feels natural.
Read on to learn why it's actually completely safe — and encouraged — to let your knees move past your toes. Plus, how to do it while keeping your knees happy.
4 Reasons You Should Let Your Knees Go Over Your Toes
There are many reasons to allow forward knee movement when squatting and lunging. Our experts shed light on what you stand to gain if you let your knees go forward, as well as potential downsides to keeping your knees back.
1. It Prepares You for Daily Life
Allowing your knees to go past your toes can make your knee joints stronger and more resilient. Your knees are going to go past your toes in daily life sometimes — so train for it.
"There are a lot of times in everyday life when the knee goes past the toes, such as going up and down the stairs and sitting down on the toilet," Kania says.
Building strong knees that won't buckle under these everyday demands requires you to regularly expose them to healthy amounts of stress. You will actually be more vulnerable to injuries and accidents if you always avoid certain positions rather than if you expose yourself to those positions in low-risk environments.
"Letting your knees go past your toes in a controlled exercise can be beneficial in that it will create more resilience for the joint," Cooper says.
2. It Builds Athleticism
Squats and lunges are knee-dominant movements, which means it's normal for your knees to move forward and bend as you descend into the rep. One reason we train these qualities in the gym is that they're essential for staying athletic and mobile, especially as we get older.
When you walk and run, your knee repeatedly moves forward over your toe with each step you take. Your hips, knees, ankles and feet all work together in this process. When the movement at any of these joints is altered, the entire pattern is disrupted and your movement becomes less fluid.
Squatting with your hips back and knees vertical alters the default ways your body moves in and out of the gym. If you can't tolerate your knees moving past your toes, you won't be able to safely run, jump or perform countless other movements necessary for sports and daily life. Older adults who can't tolerate having their knees over their toes may experience significant difficulty walking.
3. It Works for Your Body
Every person moves differently, and bodies come in different shapes and sizes, all of which affect the way you move and get into certain positions. You can improve your mobility, learn proper form and get stronger, but you can't change your joint shape (hip capsules) or the length of your bones.
"Someone with really long legs, for example, is going to have a hard time squatting without their knees going over their toes," Cooper says. Taller people or those with longer legs will naturally see more forward knee movement than those with shorter legs.
If you have a large stomach or breasts, the opposite may be true and you will naturally reach your hips back further and see less forward knee movement as you squat. The important thing is to work with the movement of your body while still maintaining proper squat form.
4. It Protects Your Hips and Back
When you limit forward knee movement, you may actually cause harm to other parts of your body.
"If you adjust one thing, like where your knees are, another area of the body is going to pick up the slack or have to deal with the load," Cooper says.
Shifting the hips back to avoid forward knee movement transfers more force to your hip joint and sometimes your lower back. This temporary band-aid may eventually lead to pain and problems throughout your body.
When You Shouldn't Let Your Knees Go Over Your Toes
Despite the benefits of allowing your knees to go over your toes, it's not for everyone — at least not right away.
"Just like with anything we do in the gym, if we do too much too soon or something we're not quite ready for, it can lead to problems," Cooper says.
Consider your history with knee pain. "For those that may have had knee injuries in the past, have arthritis or are coming off something like a knee replacement," Cooper says, "it might be beneficial to keep your knees behind your toes."
Another rule of thumb is to never push through joint pain while training. "If any movement causes knee pain because the knee goes past the toes, I would hold off on encouraging going knee past toes," Kania says.
Start building stronger legs with exercises that don't cause pain. Box squats, split squats, step ups and posterior chain exercises (think: leg curls, deadlifts, glute bridges) may be good choices. At the same time, make sure you're learning to how to use your feet and regularly working on your ankle and hip mobility.
Eventually you can retest your ability to squat and lunge with knees under toes under the guidance of a trainer or medical professional. Ideally, restricting forward knee movement will be a temporary fix that you use only as necessary.
So, How Bad Is It Really for Your Knees to Go Over Your Toes?
If going knees-over-toes feels natural, then, by all means, let them do that. It's normal, and even beneficial, for your knees to move forward past your toes. You shouldn't restrict forward movement in your knees to prevent injury or reduce stress on your joints.
"The knee joint is pretty resilient when it comes to exercises and even everyday life," Cooper says. "Overall, letting your knees go over your toes isn't a bad thing that it's made out to be."
The Right Way to Let Your Knees Go Over Your Toes
When it comes to squats, it's important to realize that there's a right — and a wrong — way to let your knees go past your toes.
A good squat starts with strong feet. It's important to grab the ground with your toes and keep your heels on the floor throughout the entire rep. If you shoot your knees so far out past your toes that your heel comes off the floor, your form (and your knees) will suffer.
This can happen when you initiate your squat by dropping straight down. You bend first at the ankles, shooting the knees out over your toes without moving your hips.
Instead, think about sitting both back and down as you start your squat. Your hips should move backward as your knees move forward. Squatting like this allows you to keep your feet on the floor and evenly distribute the load throughout all your lower body joints.