Low back on the way up of squat

Question

I need some advices to understand if my low back posture is correct while squatting.

Let's consider these pictures of me, referred to the way up of squat:

• Picture 1): I've arrived at the parallel. I don't usually try to go too much lower, since it's difficult for me to keep the correct position during this phase. So, since I'm learning, I want firstly to improve my general posture during squat. In this picture, my lower back has its natural curve (natural lumbar lordosis), so I think it's fine.

• Picture 2): I'm on the way up. Let's focus on the red circle. As you may see, for an istant there is a little bulge on my lower back. I've noticed that this happens not only in squat, but in general when my abs are squeezed and my back is not extended forward. If I try not to squeeze my abs, this bulge won't exist, but of course abs must be kept thight during all the exercise.

• Picture 3): I'm arrived at the final position. The low back curve is natural, so I think it's fine.

As you have seen, my doubt regards picture 2. Why does squeezing my abs cause such a little bulge? Is it physiological? Is it correct? Is it natural? Or should I do something to avoid it.

Answer 1

Your posture is fine, but you could probably still work on maintaining a more neutral spine if that's important to you

It looks like you have mild lumbar flexion when you squat, meaning that your lower back is being pulled into a flat position, rather than a neutral position (being slightly curved inwards). Since this is a body-weight squat, there's no external load that could be pulling you into lumbar flexion, so it must be coming from your abs instead.

This isn't a major problem, and it's certainly not like this is going to cause an injury, but if you'd like to maintain a more neutral spine throughout the squat, learning to brace properly may help.

Bracing in the squat is achieved through the contraction of the abs and spinal erectors together and in balanced opposition to each other, combined with a full breath hold. When you begin bracing, the spine should not initially move. If you find that when you begin tensing your abs in a standing position that your shoulders move forward slightly, that indicates that the ab tension is not being balanced by your spinal erectors, and your abs are pulling your spine into lumbar flexion. You can also try this while lying on your back - the hollow arch underneath your lower back that exists while you are relaxed should not disappear when you brace. Try to avoid thinking about flexing your abs, because that's usually associated with lumbar flexion, and instead learn to feel bracing as a separate action.

Useful cues for bracing include focussing on trying to pull your ribcage down towards your pelvis without letting it tilt forwards. If you still experience lumbar flexion, try focussing on pulling your shoulder-blades towards your butt.

Mastering bracing will be valuable if or when you begin squatting with external loading.

Answer 2

The picture is a little blurry but this could be pelvic tilt, specifically posterior pelvic tilt. It can be caused by solely contracting your abs. This rotates your hip joint clockwise, with respect to the photos.

To maintain a more neutral tilt, you counter this rotation by contracting your glutes. The glutes function to extend the hips (counterclockwise). To get a sense of pelvic tilt, get into a half-squat, keeping the torso and leg position fixed, and rotate only the hip joint.

You should be contracting both the abs and glutes isometrically, when squatting. This keeps the core rigid (they counter-oppose each other) and transfers the load to the primary movers (quads, hamstrings, glutes). Lack of rigidity results in the muscle compensation throughout the movement, which ingrains poor posture and movement patterns. This assumes you have good posture while standing; posture issues can interfere with the squat movement pattern and will need to be addressed separately.