squats facts

Squat Facts – Lay the Myths to Rest


Squat – A natural movement

Crouching down is a natural movement. Almost all of us did it as infants to pick something up and it is common in many parts of the world as a waiting position or for food intake. By the way, those are part of the world, where back disorders are not the number one disease of the population! Also, nobody there is walking on crutches because he has damaged his knees by spending too much time in a crouched position.

For thousands of years this has been a typical position for the human and his ancestors. When an adult crouches, it looks – if there are no impairments of the involved joints or other movement restrictions – approximately like this:


Can everybody do squats?

Provided that a person is healthy and has normal flexibility, he can do a squat – as he could when he was an infant. Many people, however, lose this ability as their life goes on. As kids start school, most of the day will be spent seated., This leads to movement restrictions in the range of motion below the seated position, often resulting, over the years, in knee and back pain. This has reached a point where doctors say: Sitting is the new smoking!

Depending on flexibility, length of the torso and the relation of thigh to lower leg, the squat looks different from person to person. Like you can see on the previous pictures,you have to push your knees over the toes –this is the only way to get into the deep squat position and bend and train the knee over the full range of motion.

Understanding the squat as a strength exercise

A Squat is a strength training exercise, its eccentric component includes the complete bending of the knee joint and a partial bending of the hip joint and the ankle joint. In other words: a Squat is a movement that includes the natural crouching and standing up again.

For some people, the own bodyweight provides enough resistance in this exercise. For people with very little musculature or those who are very obese the bodyweight might even be too much for a single repetition. As soon as the own bodyweight doesn’t provide a sufficient training stimulus for the given goal, though, you do what defines strength training: you increase the resistance, which means you add weight progressively.

In the case of the most common Squat in strength training (the Back Squat, which this article is about) this is achieved by placing a barbell on your upper back:


The difference between the natural movement and the strength exercise therefore is the additional weight.

But it is bad for the knee joints to push your knees over your toes, isn’t it?

Poorly educated trainers, doctors or physiotherapists who have not understood the biomechanics of the knee properly or people who train but are not able to perform deep squats themselves often spread the following myth: “It is harmful to push the knees over the toes.” That is complete nonsense! As we have learned so far in this article, it is a completely natural motion sequence. You can`t walk stairs up or down in a normal way without pushing the knee over the toes. The knee joint is made to get flexed and extended.

In a study about this subject, researchers from the University of Memphis, Tennessee, compared Squats with the thighs parallel to the ground while pushing the knee over the toes with Squats in which pushing the knees over the toes was limited by a wooden board (see picture):


As you can see it is not a deep squat, as this is not possible if the knees have to stay behind the toes. But even with the parallel Squat (thighs parallel to the ground), huge differences occurred.

This were the results of the study:


As you can see, the knee torque during the unrestricted Squat (A) was slightly higher than when performing the restricted Squat. The hip torque however was over 1000% higher during the limited Squat compared to the Squat in which the knees were pushed over the toes.

What does that mean?

Either the stress is on the knees or it will be put on the lower back/ the spine through the excessive forward lean (which transfers the center of mass forward to balance the backward shift of the bottom). Biomechanically this is fundamentally more unfavorable than the slightly higher stress on the knees and a clearly worse position for the intervertebral disks.

In an optimally executed Squat the stress will be distributed on knees and back. As the world’s most successful strength coach Charles R. Poliquin explained in his Advanced Strength Program Design Seminar: crucial for the compression of the lumbar spine is the horizontal distance between the barbell and the fifth lumbar vertebra (L5).

As the study showed as well this means:

The more upright someone is during the Squat the better it is for his back and his hip.

Why is it bad if you perform Half-Squats only?

Because you destabilize the knee by doing them! You only train in the upper part of the range of motion. This way you lose, as illustrated in the saying “Use it or lose it”, mobility, strength and joint-health in the part that is not being trained, while the strength in the trained part increases. This is a guarantee for muscular imbalances and in the worst case degeneration and injuries. More on this later.

But don’t deep Squats harm the knees?

Healthy knees will not be harmed by a correctly executed Squat, which means a Squat so deep that the hamstrings preferably cover the calves completely – so the exact opposite is true!

Deep Squats are necessary to:

  • stretch the soft tissue in the lower body and to improve flexibility.
  • ensure gristle health in hip, knee and ankle joint.
  • improve ankle joint mobility and thereby knee health.
  • train the VMO and thereby increase knee stability and sprinting and jumping performance.

The gristle in our joints is supplied with nutrients by compressive stress, similar to a sponge after being compressed in the water. If such compressive stress is not being applied in specific ranges of motion it impairs the gristle, making it brittle and thereby more prone to degeneration and injuries.

In the same way, our musculature is only getting strong in the areas where we are stressing it. In the case of the Squat, the muscle which is most active in the first 15% of extension (so the lowest part of the Squat) is the Musculus Vastus Medialis Obliquus (short: VMO). This muscle is very important for sprinting and jumping performance and a crucial factor for knee stability.


It is a sign of weak VMOs when the knees drive inwards during a Squat (middle picture).
If the VMO can’t stabilize the knee during high external forces, serious injuries can be the outcome (right picture).

By the way, thigh and shank do have the least contact in the knee joint at 90° and hence are stressed most at this point. Below 90°, thus in a deep squat, the stress starts to decrease. Also you can use less weight in this position and thereby relieve the passive structures.

What About Heavy Weights?

But heavy weights are no problem either, if you train over the complete range of motion. Provided that you get used to those heavier weights step by step within an intelligent strength training program, there is absolute no harmful stress on the body. The healthier the knee joints are the higher the potential performance in the Squat is. Not without reason Olympic weightlifting belongs to the sports with the lowest rate of injuries – knee injuries included! And this despite the fact that the lifters move weights that are unachievable for the average Joe. Think of soccer in comparison…


Dimitry Klokov, Russian weightlifter, World Champion and Olympic Silver Medalist performs a Squat. As you can clearly see, his knees are far in front of the toes and his torso is very upright.

By the way, the most frequently injured joint in weightlifting is the shoulder, not the knee.

Why are so many people at commercial gyms doing Half Squats nevertheless?

The most “Squats” you can observe in a gym look something like that:


Why is that so?

The people who train properly (there are not many of them) don’t do Half Biceps Curls or a Half Bench Press. Why, of all things, should the knee joint be the one single joint that you do NOT have to train over its full range of motion? In my opinion, people don’t do deep Squats…

  • Out of ignorance and because they are misinformed. Many fitness and bodybuilding magazines contain bad or even wrong information. The internet can be curse and blessing at the same time. Since anybody can call himself an expert here and falsehood is rampant it is difficult for the layperson to distinguish. The same is true for advice you get at the gym. A big arm or the fact that someone can bench press a lot does not necessarily mean that this guy has expertise in intelligent strength training. Or knows how to train other people beside himself.
  • Out of ego. The deeper the Squat, the smaller the weight you can use. Often the technique gets sacrificed on the altar of weight. Something similar can be observed for almost every other exercise. The bar is not touching the chest during the Bench Press. The arms are not fully extended during the Chin Up. And the pad is not being touched with the forearms during the Scott Curl. “Range (of motion) before load” should be the guideline to get optimal results regarding gains of strength and muscle and to stay free from injuries.
  • Out of lack of flexibility and lack of knowledge about how to improve and compensate it. Often there is a lack of well-trained staff in gyms and sports clubs.

And what about the Powerlifting Squat?

Powerlifting consists of lifting the most possible total weight in the three exercises Squat, Bench Press and Deadlift.

It is not about joint-friendly exercise execution, muscular balance or the largest ranges of motion possible. All movements are aimed to move as much weight as possible over the shortest possible distance.

According to the rules, while performing the Squat, the athlete must bend the knees and lower the body until the top of the legs at the hip joint is lower than the top of the knees. The barbell is placed much lower on the back to keep the leverage for the hip extending muscles as short as possible. For the hip is the joint moving the major part of the weight and getting stressed the most.

So regarding this sport it is the correct execution. Because it allows you to move the most weight over the given range of motion. But this execution is not optimal in terms of health or the athletic transfer on other sports. As the attentive reader of this article should know by now. In this sport, the knee extending musculature is being trained only partly. And also never being trained in the lower range of motion.


This will lead to the problems mentioned above. Like too much stress on the back and hip as well as destabilization of the knee joints. Many powerlifters develop hip pain because of the unidirectional training of the musculature.

Do I have something against powerlifters for this reason or would I refuse to train one? Of course not! But I would train him in a way that ensures full range of motion and muscular balance. Before starting with the more specific training and the Powerlifting Squat.


  • The only Squat that is healthy long-term is the deep Squat.
  • The knee has to be pushed over the toes when you perform a Squat.
  • The more upright you can stay while performing a Squat, the less stress on the spine.
  • Deep Squats make you more flexible and provide healthier joints in the lower body.
  • They improve knee stability and prevent injuries.
  • They improve sprinting and jumping performance.

This article is supposed to educate. The more people know how to train intelligently, the better for all of us. Switch your egos off and common sense on and do deep Squats. Or look for a competent trainer who teaches you how to do them. And the next time someone tries to dissuade you from doing deep Squats show him this article – you know better!

Philip Schmieder has a Diploma in Sports Science. He works as a self-employed Personal Trainer at the Urban Athletes Gym in Cologne, Germany. Following his academic career, he continued to educate himself by taking courses with, among others, Charles R. Poliquin (Advance Program Design, Metabolic Analytics Practitioner). You can contact him on his Website: www.schmiedertrainer.de .