Lower back pain during squats almost always comes from your spine absorbing forces that should be distributed across your hips, glutes, and legs. This happens when your pelvis tucks under at the bottom of the squat, when tight ankles or hips force your torso to compensate, or when the weight simply overwhelms your core’s ability to keep your spine stable. The good news: most squat-related back pain is fixable with form adjustments or targeted mobility work.
What’s Actually Happening to Your Spine
During a squat, your lumbar spine (the five vertebrae of your lower back) should maintain a gentle natural curve throughout the movement. When that curve flattens or reverses, compression and shearing forces on your spinal discs spike. This is the core mechanism behind most squat-related back pain, and it can be triggered by several different problems working alone or together.
The most visible version of this is called “butt wink,” where your pelvis rotates backward at the bottom of the squat. When viewed from the side, your tailbone tucks under and your lower back rounds. This happens when you’ve used up all available hip flexion range of motion and your body borrows extra depth from your lumbar spine instead. A small amount of pelvic tilt at the very bottom of a deep squat is common and not necessarily harmful, but if the tilt is excessive or starts before your thighs reach parallel, it significantly increases the load on your intervertebral discs.
The Most Common Causes
Limited Ankle Mobility
This is one of the most underappreciated causes of lower back pain in the squat. When your ankles can’t bend forward enough (a movement called dorsiflexion), your body compensates by leaning your torso further forward and flexing more at the hips and lumbar spine. Research comparing people with limited ankle dorsiflexion (under 30 degrees) to those with normal range (over 35 degrees) found that the restricted group had significantly greater forward trunk lean, more lumbar spine flexion, and more pelvic movement during squats. All of that extra motion translates to more stress on the lower back.
A quick test: face a wall with your toes about four inches away and try to touch your knee to the wall without your heel lifting. If you can’t do it, limited ankle mobility is likely contributing to your back pain. Elevating your heels on small plates or wearing squat shoes with a raised heel can provide immediate relief while you work on improving the range over time.
Tight or Shallow Hip Joints
Your hip sockets determine how deep you can squat before your pelvis is forced to tuck. Some people have deeper hip sockets or a different angle where the thigh bone meets the pelvis, which limits how much hip flexion they can achieve. A condition called femoroacetabular impingement, where the shape of the hip joint creates a bony block, is known to alter squat mechanics and can force compensatory movement through the lower back.
Tight hip flexors and hamstrings produce a similar result through soft tissue restriction rather than bone structure. Either way, when the hip joint runs out of room, the lumbar spine picks up the slack.
Weak or Poorly Coordinated Core Muscles
Your core muscles act as a brace that keeps your spine rigid under load. When these muscles fatigue, lose tension, or simply aren’t engaged properly, your lower back rounds under the weight. This is why back pain from squats often appears only at heavier loads or toward the end of a set: your core gives out before your legs do. Poor instruction on how to brace the trunk and pelvis during squats is a commonly reported cause of the problem.
Bar Position and Torso Angle
Where you place the bar on your back changes how much your torso needs to lean forward, which directly affects spinal loading. A high bar position (bar resting on the upper traps) keeps you more upright, producing less hip flexion and less load on the lower back. A low bar position (bar sitting across the rear deltoids) requires a greater forward lean, which concentrates more force in the lower back and hips. On paper, the more upright you are, the less pressure on your lower back. If you squat low bar and your back hurts, switching to high bar or front squats can reduce lumbar stress while you address the underlying issue.
Muscle Strain vs. Disc Pain
Not all lower back pain from squatting points to the same problem. The type of pain you feel offers useful clues about what’s going on.
A muscle or ligament strain feels like a sudden, stabbing, localized pain, usually on one side or across the lower back. It gets worse when you contract the muscle or twist your torso. You might notice swelling or tenderness right over the strained area. This type of injury typically heals within a few days to a couple of weeks with rest and gradual return to movement.
A bulging disc produces pain in the lower back that radiates into the hips, buttocks, or legs. It tends to be worse with activity and feels better when you rest. A herniated disc, which is a more advanced version of the same problem, is more likely to irritate nearby nerves and can cause numbness, tingling, or weakness in one or both legs, though it usually affects only one side.
The distinction matters because muscle strains respond well to short rest and modified training, while disc issues often need a longer, more structured rehabilitation. Pain that stays localized to your lower back is generally less concerning than pain that travels down your leg.
Warning Signs That Need Medical Attention
Most squat-related back pain is muscular and resolves on its own. But certain symptoms indicate something more serious is happening. Pain that spreads down your leg, numbness or weakness in one or both legs, or any loss of bladder or bowel control after a squat session warrants prompt medical evaluation. Pain combined with fever or chills also falls into this category. These symptoms can indicate nerve compression or other injuries that won’t resolve with rest and form corrections alone.
How to Fix It
Start by identifying which limitation is driving the problem. Film yourself squatting from the side with a light weight or just your bodyweight. Watch for when your lower back starts to round, how far forward your torso leans, and whether your heels lift off the floor. Each of these tells you something different.
If your heels rise or your torso pitches far forward, work on ankle dorsiflexion. Weighted wall stretches held for 30 to 45 seconds, done consistently for several weeks, can add meaningful range. In the meantime, squat with your heels elevated on a wedge or plates.
If your back rounds well before you reach parallel depth, hip mobility is likely the bottleneck. Experiment with a wider stance and slightly turned-out toes, which opens up more room in the hip socket. The 90/90 hip stretch and deep goblet squat holds (sitting in the bottom of a squat with a light weight at your chest) can gradually improve range of motion.
If your back rounds only under heavier loads or toward the end of a set, your core is the weak link. Practice bracing before each rep: take a deep breath into your belly, tighten your abdominal wall as if someone were about to punch you, and hold that tension throughout the entire rep. Dedicated core work like planks, dead bugs, and Pallof presses can build the endurance your spine needs under load.
If you squat low bar, try moving the bar higher on your traps or switching to front squats temporarily. Reducing the forward lean even a few degrees can take meaningful pressure off your lower back while you build the mobility and strength to handle your preferred position. Reducing squat depth to parallel rather than going as deep as possible also limits how much pelvic tuck can occur, keeping your lumbar spine in a safer range while you address the root cause.