You should set up for a squat with your feet shoulder width apart and toes flared out 30°. The Knee should stay perfectly aligned with your second toe. If you look from side , your torso and shins should be parallel.

The fact is not two human body are exactly same. For example, differences in limb lengths and femuro pelvic structure affect the way we squat. Short of limb lengthening surgery, these factors are non-modifiable. The height also matters in squat. If you are tall and do squat. You lean more forward as compare to short height person. This is because  femurs are often longer relative to their torsos and tibias in tall person. Femoral angle and acetabular position contribute to squat depth and alignment.

Perhaps you’ve seen recommendations to squat like a baby. In reality, Its impossible. One of the reasons babies are able to squat so effortlessly is because their heads weigh a ton relative to the rest of their bodies.. Unrestricted ankle dorsiflexion allows the knees to translate forward over the toes. This allows proper squat mechanics. If ankle mobility is restricted, squat pattern affected. You may seen many clusters of sign in squat.

There are few features that we look at squat. These are heels to remain in contact with the ground, unintended knock-kneed position, to avoid excessive dynamic lumbar flexion under heavy load.

Sometimes these features can not be seen during squat. If someone’s heels  elevated from the ground, they can do squat with their heels elevated. Many elite power lifters and Olympic lifters purposely allow their knees to visit valgus as their ascend in their squat. This movement strategy enables them to lift more weight. Finally, some degree of lumbar flexion occurs every time we squat. For most people, it’s perfectly safe, especially if loading is submaximal and has been applied progressively over time.

Anatomical differences necessitate deviations in terms of foot width, toe flare, depth, and torso and shin angles. On the other side of the coin those who are doing squat has simply selected the strategy that’s right for them based on their unique structure.