Squat Myth: Can the knees go over the Toes?
In a previous blog I look at the optimum depth of squats and debunked the myth that deep squatting is bad for your knees.
Athletes without a history of knee injuries can perform full depth squats without being concerned about injuring their knees (stretching their ACLs and PCLs) given proper training methods. They should squat ass-to-grass providing they have a good technique and they don’t max out every day.
Another common squat myth is: The knees should NEVER go over the toes!
Somehow within the fitness world and in some medical professions some people believe, ‘that the knees should never go past the toes while squatting’. No one knows where this myth started though. The instruction is even a part of the National Strength and Conditioning Associations (NSCA) guidelines for how to teach a proper squat (1). Is it really that dangerous?
Knees over Toes?
When an athlete squats with a poor technique, they often start by driving the knees forward to initiate the squat. As the ankles dorsiflex it causes the centre of gravity to shifted forward onto the balls of the feet. This type of squat fault has been called the “knees first” approach. Squatting this way leads increases the shearing forces on the knee joint and contributes to increased risk of injury and potentially eventually to pain (2).
Incorrect Squat Knee First
At first appearance this issue would appear to be a problem of the knee. An athletes who squat poorly by moving their knees forward often develop knee pain. Therefore limiting forward movement solves the problem? The originators of the cue were probably well-intentioned coaches or physiotherapist trying to rectify this issue. Limiting the knees from moving forward only addresses the symptoms of a bigger problem… BALANCE!
The knee is a hinge joint. It will only move forward based on what is happening at the ankle and hip. We should really focus on the hip and ankle joint when we squat. Instead of concentrating on what is going on at the knee.
One of the fundamental concepts when squatting is maintaining the centre of gravity over the middle of our foot. The foot tripod providing a stable foundation that allows our body to remain balanced and work efficiently to produce strength and power. The calcaneus (heel) is the first contact point. The medial contact point of the tripod is the first MTP joint or the first metatarsal head (ball of the foot). The lateral contact point is the head of the fifth MTP joint (base of the pinky toe).
During a bodyweight squat the centre of gravity is located just above the naval. When back squatting with the barbell the centre of gravity is raised. The efficiency of the movement is dictated by how well we can balance the centre of gravity within the foot tripod (middle of the foot).
When the athlete initiates the squat by driving their knee forward the athlete’s centre of gravity is shifted forward onto the balls of their feet. Therefore the cue to limit the knees from moving forward is actually ensuring the athlete stays balanced.
Unbalanced Squat Balanced Squat
Initiating the squat from the hips
Using the cue ‘break at the hips’-’drive the hips back' or ‘sit back into the squat’ will engage the posterior chain of the body. This allows the athlete to move from their hips first instead of their ankles when they start to decend into the squat. This automatically loads tension into powerhouse muscles of the body, the glutes. This posterior engagement will also limits early forward travel of the knees. This allows the athletes to maintain their centre of gravity over the middle of the tripod foot.
Correct Squat Hip First
This cue only works so far into the squat, there comes a point that in order to achieve optimum depth the knees must eventually move forward. In order to achieve full depth in the squat there comes a time when the knees must travel forward over the toes. The deeper we squat, the more the knees will have to move forward in order to remain balanced. This simple concept can be hard to grasp for some people..
In order to reach full depth in the squat, the hips must eventually be pulled under the torso. This allows the athlete to remain balanced and keep the chest upright. Because the knee is a hinge joint this moves is dictated at what happens at the hip and ankle, the knee will be forced forward at this point.
Proper Transition into Bodyweight Squat
It is very common for athletes to have their knees move forward even past their toes (if their ankle mobility allows). It comes down to weight distribution and the ability to maintain the centre of gravity over the tripod foot.
We should be concerned on when the knees more forward past the toes, not if.
Low Bar Back Squat
The low-bar back squat is a technique primarily used by powerlifters. The bar is positioned further down the back over the middle of the shoulder blade (scapula). The athlete will initiate the squat with the “hips back” approach. This creates an increased inclined trunk position and allows the bar to remain balanced over the middle of the foot. The majority of the weight is lifted through the power development of the hips. With this technique there is minimal forward travel of the knees (5). Because our hips and glutes are extremely strong, it’s common for elite powerlifters to squat in excess of 450 kg
However, the low bar squat technique can only descend to a certain point (to parallel or just below). If an “full depth” squat were to be attempted with the low-bar back squat, the athlete would eventually fold in half.
High-Bar Back Squat
The more common technique you’ll witness in weightlifting is the high bar back squat. Athletes will use the high-bar back squat, front squat and overhead squat techniques. As these squat patterns resemble the positions an athlete will transition through during the competition lifts of the snatch and clean & jerk. These squats require a more balanced approach between the hips and knees in order to maintain an upright trunk position. Athletes must descend as deep and as quickly as possible in order to get under the bar during the clean or snatch. By allowing the knees to move forward at the right moment, the weightlifter can descend into a deeper clean or snatch without falling forward.
While shear forces have been shown to increase in the deep squat position with forward knees, the body can handle them appropriately without risk for injury (2). If done correctly with the squat initiated with the “hip first” technique, the knees going past the toes is not only safe… but necessary to successfully completed the deep squat.
Summary
Someone who moves poorly will initiate the squat with a “knees first” approach. An athlete who moves with optimum technique will start the squat by move the hips back.
Research has demonstrated that the knees of healthy athletes are relatively safe in the bottom of a deep squat (2,6). As long as loading is programmed correctly and good technique is maintained, the knees have to move past the toes at the bottom of the squat in order to allow the hips to achieve a deep position.
“The question is not where does the knee go, as much as where is the weight distributed and what joint moves first” Michael Boyle, strength coach (3).
An optimal squat is about the hips initiating the movement and maintaining the centre of gravity over the tripod foot.
Resources
3) Boyle M. “Knees over toes?” Strengthcoach.com. Web. 25 Jan. 2016.