Just kidding. You definitely should.
This is my first post of a ‘Myth Monday’ series that I will hopefully start on a weekly basis.
If you live in the physical therapy world, you will often hear the phrase, “Don’t let your knees go past your toes.” while a patient is squatting. I cringe every time I hear it because it is ridiculous, unfounded, and makes our field look like novices when it comes to natural human movement.
If you’re a physical therapist reading this, and you’re skeptical about what I’m saying, please google Olympic weightlifting squat.
You’ll find a multitude of photos like this:
In all of these photos, the athlete is squatting with their knees WELL past their toes.
One could argue that this may be good for sport performance but not overall joint health. But in a 1994 study, it was demonstrated that Olympic weightlifting was among the LOWEST injury rates when comparing it to other sports such as soccer, cricket, and track and field. That study is obviously a small sampling questionnaire and not a very high quality study. But, to my knowledge, there are no studies that indicate Olympic weightlifting is associated with greater injury rates than any other sport.
And this sport is associated with a squat stance where the knees travel WAY past the toes.
If you’re a physical therapist that skims research (we all do sometimes), you may cite the Fry, 2003 study which did state that limiting forward knee translation did significantly decrease stress at the knees.
That’s a fact.
But if you looked at what happened at other joints, such as the hip and low back, you would see that limiting this forward knee translation would do a great deal more harm overall. Limited anterior knee translation, as pictured below, resulted in a 22% decrease in knee torque but also resulted in a 1070% increase in hip torque. No thank you.
The actual torque values, from this article, are pictured here:
I’m a much bigger believer in adjusting the squat method temporarily to minimize knee stresses while still providing a loading environment for patients suffering from knee pain. This could be performed using box squats or low-bar back squats, which allow for a more upright shin and more forward trunk lean. Michael Mash does a great article about this here.
Additionally, in healthy populations, squatting should be about the individual’s goals and optimizing range of motion so that the external load remains over the individual’s center of gravity.
I really like this quote by Michael Boyle, “Many people who squat poorly tend to exhaust their available ankle range of motion first.”
I also believe squatting technique should involve which body segment initiates the squat. Knees driving forward initially may lead to increased knee joint stress. I like how Dr. Horschig puts it, “The cue to “sit back” or to “push the hips back” allows the athlete to move from their hips first instead of their ankles during the descent of the squat.” This will limit initial DF (anterior knee translation) to initiate the squat.
If you’re a physical therapist, please stop telling your patients that their knees shouldn’t travel past their toes. This idea is unfounded by research and occurs naturally in daily activities. If you’re still skeptical, please read through the research articles and blog posts, listed below, that I used to write this post.
Fry, A. C., Smith, J. C., & Schilling, B. K. (2003). Effect of knee position on hip and knee torques during the barbell squat. The Journal of Strength & Conditioning Research, 17(4), 629-633.
Hamill, B. P. (1994). Relative Safety of Weightlifting and Weight Training. The Journal of Strength & Conditioning Research, 8(1), 53-57.