There are two rules for squatting
1) The hip joint must pass the top of the knee
2) The barbell lifter system must stay in balance over the mid foot.
The Model
As the lifter starts the squat, they are to set their back angle. This requires the hips to move back, chest to point down, and the knees to move forward. At the point the back is set the hips and knees arch to get the hip crease to depth.
After the lifter has reached this bottom position, the reverse happens on the way up and the back angle is maintained. The back angle opens and the lifter will fully lock out their knees.
What can help with this visualization is image the knees travel forward then they stop. Place a wall in front of the knees. We want the knees to stop traveling any more forward, on the way down and the way up.
The timing of when the knees stop moving forward and when the back angle is set will vary based off 2 components
1) Bar Position – high bar, low bar, front squat
With beginners in low bar the back the eye and chest are encouraged to point down this promotes the use of the hips. In a front squat it is encouraged to keep the eyes forward, the chest up and elbows are high to prevent downward movement on the ascended forcing the quads to do the majority of the work.
2) Anthropometry
If we have a lifter who has a very short torso and long legs in order to keep the bar in balance, we will need to widen their stance. To keep the weight over the mid foot in any bar position squat. If we have a lifter who has a long torso with short legs their back angle whether in a low bar and high bar position may look very similar. This is due to minimal hip angle change from the 2” difference at the distal end of the back segment. Contrary to a short torso with long legs, a 2” change in bar positions will result in a great hip angle change focusing a setup change to keep the bar over the mid foot.
What You Should Know
Not everyone’s squat will look the same. Take into consideration differences in anthropometries and bar position while adhering to the 2 rules (hip joint goes below the top of the knee and the weight stays balanced over mid foot) the squat will look how it should. I recommend to manipulate set up (bar position and stance) for your best squat position.