Lower back pain after squats: soreness or a strain, depth, bar position, belts and squatting again

Soreness or a strain: what usually happenedStrong evidence

A dull ache across the lower back a day or two after a new, heavier or longer session, or a new variation such as low bar, pauses or more depth, is delayed-onset muscle soreness. In a review, it typically started 12 to 24 hours after the session, peaked between 1 and 3 days and was gone within 5 to 7 days; how sore people felt matched poorly with how much the muscle was damaged, and one session protected against soreness from the next similar one.

Sudden sharp pain or a catch during a rep, often a grinding or lopsided rep, is more often ordinary low back pain. The NHS names a pulled muscle (a strain) as a common cause, and an NHS physiotherapy leaflet says back pain can hurt a lot but is rarely caused by anything serious. In 6 years of injury records from elite US weightlifters, 74.6% of back injuries were strains, and 90.5% of all injuries cost a day or less of training.

Sources 1, 2, 3, 4

Why the squat loads the backEmerging evidence

In a squat the back muscles work hard to hold the trunk still while the hips and knees do the moving, and the further the trunk leans forward, as in a low-bar squat or with a long torso, the harder they work. So most pain after squats is the back's muscles and joints meeting more load, sets or depth than they're used to.

Squatting isn't a high-injury activity: pooled studies found 2.4 to 3.3 injuries per 1,000 hours of weightlifting and 1.0 to 4.4 per 1,000 hours of powerlifting, similar to other non-contact strength sports, with the spine, shoulder and knee commonest. In 104 Swedish powerlifters, 70% had an injury affecting their training, most often in the lower back and pelvis, but only 16% of them had to stop training. No trial has tested what causes it: a review lists very heavy loads, large ranges of movement, short rests between sessions and faulty technique as suggested causes, and in the Swedish lifters, training more often and a bigger deadlift went with being injured. In our reading, jumps in weight or volume, tired reps and going back to an old weight after a break are the commonest stories.

Sources 5, 6, 7, 8, 9, 10

Other causes to knowStrong evidence

Pain down one leg below the knee, with tingling, numbness or weakness and usually worse than the back pain, is sciatica, a trapped nerve, often from a disc; the NHS says not all slipped discs cause symptoms, and using weight-training equipment wasn't linked with a herniated disc in a case-control study. In a teenager or young adult, back pain that is worse arching backwards and builds over weeks can be a stress fracture at the back of a vertebra (spondylolysis), the commonest cause of back pain in young athletes: in clinic series it was found in 47 of 100 adolescent athletes with back pain, against 5 of 100 adults, and in 30% of 1,025 non-elite adolescent athletes with back pain. US orthopaedic surgeons name weightlifting among the sports that arch the back, with pain like a muscle strain that is worse with activity and better with rest.

Low pain on one side by the dimple at the back of the pelvis, spreading into the buttock, points to the sacroiliac (SI) joint: 94% of 50 people whose SI joint pain was confirmed with an injection felt it in the buttock. Sudden pain after a modest lift, with thin bones or long-term steroid tablets, can be a partly collapsed vertebra: the NHS says even a cough or sneeze can do this when bones are thin. And some back pain isn't the squat at all: stiffness that started before 45, wakes you in the second half of the night and eases with exercise points to inflammatory back pain, which the National Institute for Health and Care Excellence (NICE) asks GPs to refer, and pain with a fever, burning when you pee or pain in the side can be a kidney infection.

Sources 11, 12, 13, 14, 15, 16, 17, 18, 19, 20

When a scan helps, and what it can't tell youStrong evidence

Only with warning signs, or in a specialist setting when the result would change what happens next: NICE advises against routine imaging for low back pain. Scans of people without back pain often show changes: disc bulges in 30% of 20-year-olds and 84% of 80-year-olds, and disc changes in more than 90% of elite athletes, weightlifters included, which didn't match who had back pain over 15 years.

A young lifter with suspected spondylolysis is the exception. No examination test, including standing on one leg and arching back, reliably confirms it, so two-view X-rays come first, then a magnetic resonance imaging (MRI) scan, which in pooled studies picked up 81.4% of the defects found by computed tomography (CT); a CT scan is used when it persists. After sudden back pain from a modest lift with thin bones, a GP may check your bone health.

Sources 21, 22, 23, 24, 25, 18

How it usually goesEmerging evidence

Soreness goes within 5 to 7 days. New low back pain improves markedly in the first 6 weeks: across 33 groups of people with new back pain, average pain fell from 52 out of 100 to 23 at 6 weeks and 6 at a year, and an NHS physiotherapy leaflet says most new back pain improves within 6 to 8 weeks. It often comes back: 69% of 250 people who had recovered had another episode within a year, more often after more than 2 earlier episodes and with more than 5 hours' sitting a day.

Spondylolysis usually does well without surgery: in pooled studies, 83.9% of young people had a successful outcome at a year or more, though only 28% of the defects healed on scans, and 92.2% of adolescent athletes returned to sport without an operation. No one can promise a timescale.

Sources 1, 26, 3, 27, 28, 29

Keep moving rather than restingStrong evidence

In a Cochrane review (2 trials, 401 people), advice to stay active gave slightly better pain relief and function than advice to rest in bed. NICE encourages people to carry on with normal activities and to consider an anti-inflammatory at the lowest dose for the shortest time; paracetamol on its own and routine opioids aren't recommended. The NHS says don't stay in bed for long periods, and suggests an ice pack or a heat pack wrapped in a tea towel.

Sources 30, 21, 2

Exercise is the treatment for back pain that lastsStrong evidence

In a Cochrane review of 249 trials of long-lasting low back pain, exercise cut pain by about 15 points out of 100 compared with no treatment, usual care or placebo (moderate certainty), and by about 9 points compared with other treatments, with mostly minor side effects such as muscle soreness. NICE recommends exercise. No trial has tested a return-to-squat programme, so this guide's plan builds the squat back in stages, as our deadlift guide does for the deadlift.

Sources 31, 21

Your lower back rounds a little under a bar anywayMixed evidence

In 30 trained lifters squatting with half their body weight on the bar, the lower back rounded as soon as the bar was on their shoulders, and bent by about 13 degrees in women and 26 in men on the way down. In a meta-analysis of 11 low-quality studies, how much people bent the lower back while lifting wasn't a risk factor for back pain starting or lasting, and a review of 41 reviews found no agreement that any posture or physical exposure causes back pain.

No study has linked 'butt wink', the pelvis tucking under at the bottom of a squat, with injury. What the evidence can't settle is whether heavy, tired reps in which the back changes shape a lot carry more risk, so the practical rule is to squat only as deep as your back keeps its shape under a heavy bar.

Sources 32, 33, 34

Depth, bar position and stance: one clinical commentary and lab studiesEmerging evidence

No trial has tested any change to the squat in people with back pain. A clinical commentary, which is expert opinion and the lowest level of evidence, advises less forward lean, a slightly wider stance and squatting only as deep as the lower back stays neutral. Lab studies point the same way: low-bar squats lean the trunk further forward, with more back muscle activity, than high-bar squats; in 15 trained people the front squat worked the leg muscles as well as the back squat with less compression at the knee; and in 12 powerlifters lifting 30 to 70% of their maximum, a wide-stance box squat put the smallest peak load on the spine of three squat styles.

Depth itself isn't the problem for most people: a review of more than 164 articles found no evidence that deep squats learned with good technique raise the injury risk to passive tissues. Letting the knees travel forward over the toes is fine too: stopping them made the trunk lean and bend more in a lab study of 30 people.

Sources 6, 5, 35, 36, 37, 38

A belt is a performance aid, not a back treatmentStrong evidence

NICE says don't offer belts or corsets for low back pain, and a Cochrane review found moderate evidence that lumbar supports were no better than nothing at preventing back pain (7 trials, 14,437 people), with conflicting trials for treating it.

In the lab, a belt raised the pressure inside the abdomen in heavy deadlifts and squats, cut modelled spinal compression by about 10% only when the lifter breathed in first, and in 49 men and women added reps (8.1 against 6.5) and felt more stable, though measured balance didn't change. In a survey of 245 German powerlifters, belt users reported more lower back injuries, which may mean people with sore backs reach for one rather than that belts cause injury.

Sources 21, 39, 40, 41, 42, 43, 44

A young lifter's back: the stress fracture evidence comes from competitive lifters and clinicsEmerging evidence

In a clinic series, 47 of 100 adolescent athletes with low back pain had spondylolysis, against 5 of 100 adults. In weightlifting, the figure comes from a 1990 series of competitive weightlifters, of whom 22.68% had it, against 3 to 7% in the general population. These figures come from competitive lifters and teenagers seen in clinics, not recreational lifters, so how often it affects people who squat in a gym is unknown. US orthopaedic surgeons name weightlifting among the sports that arch the back.

Without surgery, 83.9% of young people had a successful outcome at a year or more in pooled observational studies (665 people), and a brace made no difference to that outcome; 92.2% of adolescent athletes returned to sport without an operation.

Sources 14, 45, 46, 16, 28, 29

Holding your breath under a heavy barEmerging evidence

A held breath under a heavy load raises blood pressure steeply: up to 320/250 millimetres of mercury in 5 bodybuilders doing a heavy leg press, a lab study. A review says a brief held breath is unavoidable above about 80% of maximal effort, and its proposed health risks are unconfirmed; pressure inside the abdomen in squats can exceed 200 millimetres of mercury. The NHS says a bleed on the brain (subarachnoid haemorrhage) may be more likely when lifting something heavy, which is why a sudden, extremely painful headache during a lift is a 999 call.

Sources 47, 48, 49, 50

Find the direction that eases itEmerging evidence

In a trial of 312 people with low back pain, 74% had a direction of movement, bending forward or arching back, that eased their pain, and exercises matched to it did better than opposite or general exercises; a third of the people given mismatched exercises dropped out within 2 weeks. That is why the first stage asks you to try both and keep the one that helps. It is one trial, in people with back pain in general rather than lifters.

Source 51

What to change in the squat (written steps)

No trial has tested these changes in lifters with back pain. The stance, depth and lean changes come from one clinical commentary, which is expert opinion; the rest come from lab studies or the site's squat guide, or are our suggestion, as each step says.

• 1. For the first days, no heavy squats, good mornings or maximal attempts. Walk, and train what doesn't hurt, such as your upper body or a bike (our suggestion).
• 2. When you go back, start at about half your usual working weight for sets of 5 to 8 with 3 or more reps to spare, and add about 5 to 10% a week while your back passes the pain rule (editorial, borrowing the 2 to 10% steps the American College of Sports Medicine gives healthy adults).
• 3. Add one thing at a time: load, then sets, then how often you squat (our suggestion: heavy loads and training more often went with injury in powerlifters).
• 4. Squat to a box or bench set at the depth where your lower back keeps its shape, and lower it over the weeks (the clinical commentary's depth rule).
• 5. Use a more upright squat for now: a goblet, front or high-bar squat rather than a low-bar one, with a slightly wider stance and less forward lean (the commentary; in lab studies, low-bar squats leaned further forward with more back muscle work, and a wide-stance box squat put the least load on the spine).
• 6. Let your knees travel forward over your toes: stopping them made the trunk lean and bend more in a lab study.
• 7. Stop 2 or 3 reps short of failure, and film a set: if your lower back changes shape a lot as the set goes on, or your hips shoot up first, end the set or lighten the load (our suggestion, as in our deadlift guide).

Sources 6, 54, 10, 9, 5, 36, 38

Bar position, breathing and the belt (written steps)

Our 3D figure can't show these. The bar position and breathing steps are the site's squat and breathing guides' advice (editorial), and the cautions are the barbell squat move page's.

• 1. Rest the bar across your upper back on the muscle (the upper trapezius), not on the bony bump at the base of your neck, with your hands as narrow as your shoulders comfortably allow (editorial).
• 2. If a low-bar position hurts, move the bar higher on your back or to the front (editorial).
• 3. Take a breath and brace briefly only for heavy reps, and breathe out through the hardest part of the rep on lighter sets (the site's breathing guide). A held breath under a heavy load raises blood pressure steeply.
• 4. With glaucoma, high blood pressure that isn't controlled, or heart disease, don't hold your breath on the effort. With glaucoma, keep loads moderate and ask your eye team before maximal lifts; with heart disease, ask your heart team before lifting heavy (the barbell squat's move page).
• 5. A belt is optional, for heavy sets once you're back: it can add reps and feel more stable, and it cut modelled spinal compression only when the lifter breathed in first. It isn't a back treatment, and NICE says not to offer belts for back pain.

Sources 47, 48, 42, 43, 21

Outside the gym, medicines and injections

Break up long spells of sitting: more than 5 hours' sitting a day went with back pain coming back. The NHS suggests an ice pack or a heat pack wrapped in a tea towel, and asking a pharmacist or GP which painkiller suits you. NICE suggests an anti-inflammatory at the lowest dose for the shortest time, not paracetamol on its own and not routine opioids; it doesn't recommend spinal injections for low back pain, and suggests manual therapy, such as manipulation or massage, only as part of a package with exercise.

Sources 27, 2, 21