What a hip thrust asks of the hip, and what no study has measuredEmerging evidence
With your upper back on a bench, a padded bar in the crease of your hips and your feet flat, you drive your hips up until your shoulders, hips and knees line up. In 19 trained men lifting 70% of their best, the hips moved about 75 degrees and the knees about 21. The hip muscles worked hardest early in the lift, with the hip bent about 83 degrees, and least as the hip approached full extension, and the pelvis and trunk moved very differently between lifters: some arched at the top and some didn't.
Across 12 studies, the glutes worked hardest, then the back extensors and hamstrings, and the rectus femoris, the hip flexor at the front of the thigh, least. Feet further forward raised hamstring activity, and in 7 personal trainers changing foot position and the direction of the push changed every leg muscle measured except the gluteus medius. In 11 sprinters, the load at the base of the spine and the hip peaked just after the lowering phase.
No study has measured how far the hip extends at lockout, the force on the front of the hip joint, adductor activity or the bar's pressure on the pelvis in a hip thrust, and no case report or injury survey names it. So the map on this page is built from what each cause is known to do.
Sources 1, 2, 3, 4, 5, 6, 7
The bar on the hip bones, and a squeezed skin nerveEmerging evidence
The bony points at the front of the pelvis sit right under a bar placed too high. Our hip thrust guide says roll the bar into the crease of your hips, not onto your hip bones, with a thick pad, and the move page says use a proper pad. Pain or bruising there is a common complaint in what people search for, but no study has measured it, with a bar or a machine belt, so the advice is coaching and our reading.
The skin nerve of the outer thigh passes the bony point at the front of the pelvis. Squeezing it (meralgia paraesthetica) causes burning, tingling or numbness on the outer front of the thigh, and has been linked to tight clothing, belts, uniforms and seat belts; 12 people with it from tight low-cut trousers all recovered with conservative care, and a review says most cases settle on their own, with normal strength and reflexes. No case from a hip thrust bar has been reported, so the link to the bar is our reading.
Sources 8, 9, 10
A pinch at the front of the hip at the topEmerging evidence
No study has measured the front of the hip in a hip thrust. In a computer model of hip exercises, the forward force on the front of the hip joint was greater with the hip extended than bent, and with the glutes weakened to 5% of normal it rose by an amount equal to about 19% of body weight, mostly because a hamstring took over. The authors say it is untested whether avoiding hip extension beyond neutral helps people with pain at the front of the hip.
The Doha consensus on groin pain in athletes says iliopsoas-related groin pain is more likely if there is pain on hip flexor stretching, which the top of a hip thrust does to the front of the hip. So a pinch at lockout fits the front of the hip being stretched and loaded; stopping at a straight line, driving with the glutes rather than the hamstrings and a small backward tilt of the pelvis are our reading of the model and the definitions, not tested treatments. A clinical review of bridging also advises not arching past a neutral lower back at the top.
Sources 11, 12, 13, 14
Hip impingement and the labrumStrong evidence
The Warwick agreement says hip impingement syndrome needs symptoms, examination signs and scan findings together. In an NHS trial of physiotherapy for it, people were encouraged to avoid extremes of hip bending, moving the leg out and turning it in. The bottom of a hip thrust bends the hip about 83 degrees and the top is extension, so impingement more likely shows at the bottom with a wide, turned-in stance than at lockout (our reading).
Impingement shapes and tears are common in hips that don't hurt: across 26 studies of 2,114 pain-free hips, a cam shape showed in 37%, and 54.8% in athletes; labral tears showed in 54% of pain-free people across studies and in 69% of 45 pain-free volunteers on MRI. So a scan finding alone doesn't explain hip thrust pain.
Sources 15, 16, 1, 17, 18, 19
The groin, the pubic bone and pregnancyEmerging evidence
The big adductor (adductor magnus) is also a hip extensor: in a model study of 15 people, it took high forces in hip extension exercises, though the hip thrust wasn't tested. Squeezing a ball between the knees in a bridge raised glute and tummy muscle activity in 14 women. The Doha consensus defines adductor-related groin pain by tenderness and pain when you squeeze against resistance, and pubic-related pain by tenderness on the pubic bone. So a squeeze cue or a band can bring on inner thigh pain (our reading).
Pubic bone pain in pregnancy is pelvic girdle pain, which the NHS describes over the pubic bone at the front in the centre, and treats with exercises for the pelvic floor, stomach, back and hip muscles.
Sources 13, 20, 21, 22
The outer hip and the back of the thighEmerging evidence
Gluteal tendon pain mostly starts in mid-life and affects women more: in 3,026 adults aged 50 to 79, 15.0% of women and 6.6% of men had it on one side. Positions that take the thigh across the body compress the tendons, such as sitting with your legs crossed; in a hip thrust the equivalent is the knees caving in (our reading). It is diagnosed by examination, usually without a scan.
Feet walked far out shift work to the hamstrings: in 26 adults doing single-leg bridges, bending the knee to 135 degrees rather than 90 cut hamstring activity from about 75% to 23% of a maximal contraction with glute work much the same, and the authors note reports of hamstring cramping in the standard bridge.
Sources 23, 24, 25, 26
How common hip injuries are in liftingEmerging evidence
Across powerlifting studies, the hip and groin made up between 1.7% and 15.5% of injuries. In Swedish powerlifters the hip was among the three commonest injured areas, while in 245 competitive powerlifters the shoulder, lower back and knee were commonest. In one US hospital system, 83 of 982 CrossFit-related injuries (8.5%) were in the hip or groin, a third of them impingement syndrome, and the movements people recalled were deep squats, running, deadlifts and lunges, not hip thrusts.
Sources 7, 27, 28, 6
When a scan or test mattersStrong evidence
Not usually at first. The NHS starts with looking after it at home and a GP if it hasn't improved after 2 weeks, with a specialist who may do a scan. When imaging is needed, the Zurich consensus makes plain X-rays the first choice, with MRI only for more detail, because findings are common in pain-free hips.
A test matters for a fall or a leg you can't stand on, a teenager's sudden pop at the hip bone (an X-ray the same day), a hot, swollen hip with a fever, deep catching or locking, a lump in the groin, numbness spreading beyond the outer thigh or weakness, and pain that hasn't settled after 6 weeks with risk factors for a loss of blood supply to the hip.
Sources 29, 30, 17, 18
How it usually goesMixed evidence
No study follows hip pain from hip thrusts. NHS inform says new hip pain or a flare-up should begin to settle within 6 weeks in many cases. Pressure from the bar usually settles within days once the pad and bar position change (our reading). A squeezed thigh nerve mostly settles once the pressure is off, though a few people keep symptoms.
In the outer hip trial, 51 of 66 people had improved by 8 weeks with education and exercise, against 20 of 68 waiting and seeing. Hip-related pain often needs at least 3 months of exercise, and iliopsoas-related groin pain mostly settles with conservative care. No one can promise a date.
Sources 31, 10, 32, 33, 34
