Should Your Knees Go Over Your Toes?
Danielle Ivie, DPT, CSCS | Founder of Powered by Movement Physical Therapy
This question may be one of the most classic dogmas passed down through generations in the health & fitness space. To this day, I get this question at least once a month. So let’s break it down once and for all.
Should your knees go over your toes when you squat? – The short answer is YES.
The belief that your knees should not go over your toes started with a 1972 study that looked at the biomechanics of 12 weightlifters doing a squat under heavy load. Of the 12 subjects, the subject with the greatest forward knee movement also had the greatest shear force on the tibiofemoral (knee) joint. Shear force is a force that acts parallel to the joint causing the tibia (shin) and femur (thigh) to slide in opposite directions, as noted in the picture to the right. Shear force is a normal occurrence in loaded and dynamic movements and is resisted by ligaments, muscle, and joint surfaces. However, if shearing forces get too high it can result in knee pain and other injuries. This 1972 study based its conclusions that the knee should not go past your toes when squatting purely based on knee shearing forces as the knees pass over toes.
What this study did not account for:
- Squat depth: The subject with highest shear forces only squatted to 90 degrees. The remaining subjects squatted to 61 and 69 degrees (above parallel).
- Squatting technique: There was no information or control about how the subjects squatted. This means the increase in shear could be a result of very upright posture.
- Position & shear in other joints: This study did not note what position the hips, ankles or low back were in and what the shear on those joints looked like when changing positions of the knee in a heavy squat.
The nuance:
We should not create technique recommendations for multijoint movements based on the analysis of forces created in a single joint. The squat is a multijoint movement and a blanket statement like “your knees shouldn’t go over your toes” does not help anyone, and may create even more problems in your hips or low back.
A 2003 study looked at the effect of knee position on hip and knee torque in a squat, and found that knee torque was slightly greater when allowing knees to pass over toes, but if you did not allow the knees to pass over toes there was a 10 fold increase in hip torque. Restricting knee movement created significant forward lean in the torso and increased demand on the lifter’s hip by 10 times! The study concluded that it was reasonable to allow knees to pass over toes to allow for proper positioning of the lifter’s torso and more reasonable distribution of torque across multiple joints.
A 2013 study looked at loading of the knee joint and vertebral column (low back) changes with squat depth and weight and found that “[as long as] technique is learned accurately under expert supervision and with progressive training loads, the deep squat presents an effective training
exercise for protection against injuries and strengthening of the lower extremity. Contrary to commonly voiced concern, deep squats do not contribute increased risk of injury to passive tissues.”
The take home message: Your knees can safely go over your toes. Heavy and deep squats can be protective against injury. Technique matters, and there is not a one size fits all recommendation.
At the most basic level, squats technique should include: keeping your heels down throughout the range, keep weight centered over your midfoot, and allow your knees to track with your toes (avoid collapsing in or pushing too far out). Depth is relative to your capacity. Not everyone needs to squat as deep as possible, but almost everyone should squat at least parallel for strength gains and reducing risk of injury.
Squats are one of the most functional activities we can do – you need it to sit down and stand up, get to the ground to play with your kids, go to the restroom, and more. We’ve busted the myth that your knees shouldn’t go past your toes, so let’s get to squatting!
At PXM, we help active people in St. Louis recover from injury, optimize movement, and stay out of pain for the long term while reaching their health & fitness goals. With our unique approach to physical therapy, our top priority is to provide you with holistic, fitness forward healthcare that emphasizes your goals.
We get you back to thriving in the activities you love with our 3 step process:
POWER UP: Diagnose and understand the root cause of your problem.
POWER BOOST: Create a custom plan for you to restore function & get back to what you love.
POWER PEAK: Optimize performance to keep pain away for good & get stronger than ever.
Not sure if PXM is right for you? Have more questions? Schedule a Free Consultation today.
Dr. Danielle Ivie, DPT, CSCS
Powered by Movement, LLC
567 Hanley Industrial Ct., Brentwood, MO 63144
314-252-0504 | www.poweredxmovement.com