The main cause of lower back pain on the Squat is bad technique. If your round or over-arch your lower back when you Squat, you will put pressure on your spinal discs. This can result in lower back injuries like disc herniation. So it’s important you Squat with a neutral lower back.
Lower Back Rounding
The simplest way to fix lower back rounding on the Squat is to push your knees out harder on the way up and down. If your knees point forward or in, your lower back will usually round. So Squat with your heels shoulder-width apart, toes out 30° and push your knees to the side as hard as you can.
Next don’t Squat lower than parallel. Many people lack the flexibility to Squat ATG (“ass-to-grass”). If you lack the flexibility to Squat all the way down, until your butt touches your ankles, your lower back will have to compensate by rounding at the bottom. This can result in lower back pain.
Note that you must stop at parallel for the low bar Squat I do and recommend you to do on StrongLifts 5×5 to get as strong as you can. Squatting ATG requires an upright torso and high bar position. If you try to Squat ATG with the low bar position, your lower back will always round at the bottom.
Lower back rounding will also happen if you Squatted down with your lumbar spine hyper-extended. It will rarely stay arched when you Squat down, especially if you go deep. It will go back to normal which can look like rounding (“butt wink”). Stop hyper-extending and this rounding will stop too.
Lower Back Over-Arching
This is hyper-extension of your lower back, the opposite of flexion (rounding of your lower back). And it’s equally bad for your lumbar spine because it also puts pressure on your spinal discs, but in the opposite direction. So it can also lead to lower back pain and/or injuries.
I’ve been guilty of this one quite a lot in the past, because I tend towards over-arching my lower back on the Squat as well as all the other exercises. Some say it’s because of the years I spent working behind a computer, and the years before that playing videogames all day long…
Your lower back must be neutral when you Squat. Neutral means you keep its normal arch (“lordosis”). But you don’t go past it or you’ll get lower back pain. Your spine can handle compression fine, but not compression when your lower back is hyper-extended (or in flexion).
If you tend to hyper-extend your lower back – squeeze your abs harder. Think about keeping your lower back neutral by squeezing your abs as hard as you can. You don’t have to push your abs out or pull them in. Just squeeze them as if somebody was about to punch you in the stomach.
Squatting with a belt won’t protect you against lower back injury from using bad form. But it will give your abs something to push against. This can cue you to squeeze your abs and fix excess arching. I’ve found this has helped me most to stop over-arching my lower back when I Squat.
One mistake I used to make on the Squat was unracking the weight with my lower back hyper-extended. This compressed my arched spine and lead to lower back pain. Always set your lower back neutral when you unrack the weight. Normal arch, no hyper-extension of your lower back.
Uneven Back Loading
If you Squat with the barbell not centered on your upper-back, one side will have to more work than the other side. This can lead to lower back pain on one side when you Squat. Pay closer attention when you unrack the weight – put the bar centered on your upper-back on every set.
When you unrack the weight, your feet should both be under the bar. Don’t unrack the bar using a lunge movement. If one foot is under the bar, but the other behind, the bar will load your pelvis unevenly. This will can also result in lower back strains. Both feet under the bar, Squat up, then walk back.
If you Squat by driving your hips up faster than your chest, your Squat will turn in a goodmorning. Your torso will be almost horizontal with the floor while your legs are straight. This takes your quadriceps out of the movement, and forces your hips and lower back to finish your Squat.
To save your lower back stress, Squat up by driving your chest and hips at the same time. It’s crucial for the bar to stay over your mid-foot at all time. So put the bar correctly on your back, and keep your chest and upper-back tight so it can’t move up. This will prevent getting pulled forward by the weight.
For more info, read the guide on how to stop leaning forward on the Squat.
Lower Back Support
The easiest way to give your lower back support when you Squat heavy is to use the valsalva maneuver. Take a big breath while you’re standing with the weight on your back. Hold your breath and Squat down. Continue to hold your breath at the bottom. Then Squat up and breathe out. Repeat.
Holding your breath keeps your lower back safe by increasing intra-abdominal pressure. Your blood pressure will increase but it will go back to normal when your Squat set is over. The worst thing you can do for your lower back is to breathe out on the way down, or worse, at the bottom of your Squat.
Squatting with a belt will further add lower back support by giving your abs something to push against. The harder your abs contract, the more intra-abdominal pressure. The belt won’t prevent lower back injury from Squatting with bad form though. So fix your form before adding a belt.