Lateral pelvic tilt: uneven hips, leg length and what exercise can change

A small tilt is normal

On X-rays of 134 healthy adults, the pelvis tilted about 2 degrees on average, and up to about 5.6 degrees was within the normal range. About 9 in 10 people have legs of slightly different lengths, about 5 mm on average.

Sources 1, 2

The usual causes

A small difference in leg length, from the bones or from how the hips, knees and feet work, and sometimes scoliosis. Standing on blocks under the shorter leg shows which: a tilt from leg length levels out, and a curve in the spine doesn't.

Sources 3, 4, 5

Mirror checks are rough

Checking your hips by hand or in a mirror misses the true difference by about 4 to 5 mm and can't reliably show which leg is shorter. An X-ray is the accurate test.

Sources 6, 2

Usually not a cause of back pain

Studies found the same small leg length differences, and the same pelvic asymmetry, in people with and without back pain. People who stand all day with a difference of 6 mm or more may be an exception.

Sources 7, 8, 9, 10

What exercise can change

It can't change bone length. Side-hip training reduced how far the pelvis dropped in runners and, in one small trial, reduced a functional tilt in people with back pain. Using it for a lateral tilt is our inference from these small studies.

Sources 11, 12, 13

Heel lifts

A heel lift or insole helps some people with a measured difference and back pain, especially people who stand at work. Overall, the evidence is low quality.

Sources 14, 15

What it is

A lateral pelvic tilt (doctors call it pelvic obliquity) means one side of the pelvis sits higher than the other when you stand. It's different from anterior pelvic tilt, where the pelvis tips forward, and from the pelvis dropping on one side as you walk or run, which is covered below.

Sources 3, 4

How much is normalEmerging evidence

On X-rays of 134 healthy adults, the middle value was a tilt of 2 degrees, and 0 to 5.6 degrees fell within the normal range. In imaging studies, about 90% of people had a leg length difference, averaging about 5 mm; about 1 in 5 had 10 mm or more, and 20 mm or more was about 1 in 1,000. The American Academy of Orthopaedic Surgeons says more than half of people have a subtle difference, and that differences over 2 cm can begin to affect well-being.

Sources 1, 2, 3

How it's measuredStrong evidence

An X-ray of the pelvis and legs taken standing measures the tilt and any leg length difference accurately. Feeling the tops of the hip bones and slipping books under the lower side gave repeatable results, but missed the true difference by 3.8 to 5.1 mm in 34 people; a hand-held palpation meter measured hip height well but leg length less well. Blocks under the shorter leg, sometimes with an X-ray, show whether a tilt comes from the legs or the spine.

Sources 16, 6, 17, 4

Which leg is shorter?Emerging evidence

The level of the hip bones doesn't reliably tell you which leg is shorter or by how much, so a mirror check isn't a diagnosis.

Sources 2, 6

A structural difference

The bones of one leg are longer: from birth, after a fracture or an injury to a growth plate in childhood, or after a joint replacement.

Source 3

A functional difference

The bones are equal, but one leg works shorter, because of a stiff hip or knee, a flatter foot on one side, or how the muscles hold the pelvis.

Sources 2, 12

ScoliosisEmerging evidence

A curve in the lower spine can tilt the pelvis, and a tilted pelvis can produce a curve that straightens when the pelvis is levelled; the blocks test tells them apart. A leg length difference hasn't been shown to make a true scoliosis worse.

Sources 4, 5, 18

How you stand

Standing with your weight on one leg and the other knee bent tilts the pelvis. In 50 healthy volunteers, a 1 to 4 cm shoe lift bent the lower back sideways but not the upper back: the spine adapts above a tilt.

Sources 5, 19

Children

A child with a large leg length difference may limp, stand with one hip higher or one knee bent, or walk on tiptoe on the shorter side. In 20 children with differences of 0.5 to 2 cm, the pelvic tilt and the turn of the trunk matched the difference.

Sources 3, 20

The pelvis dropping as you walk

When you stand on one leg, the gluteus medius and minimus of that leg hold the pelvis level. If they can't, the other side drops (a positive Trendelenburg sign) and walking can take on a side-to-side lurch. In 24 women with outer hip pain, the sign picked out a torn gluteus medius tendon about three times in four.

Sources 21, 22

Small leg length differences and back painStrong evidence

Across studies, the average leg length difference was the same in people with and without back pain (5.1 and 5.2 mm). In 247 adults aged 35 to 54, it was 5.5 mm in those who'd never had back pain and 5.3 mm in those with disabling back pain, and a case-control study found no link.

Sources 2, 7, 8

A tilted pelvis and back painEmerging evidence

In 144 people with back pain and 138 without, pelvic asymmetry wasn't meaningfully linked with back pain, and reviews find no agreed link between posture and back pain.

Sources 9, 23

Standing work may be differentEmerging evidence

In 148 workers, a difference of 6 mm or more, found in 44 to 49% of them, went with more intense back pain in those who stood to work, but not in those who sat.

Source 10

Heel lifts and insolesMixed evidence

In 42 meat cutters with back pain and a difference of 5 mm or more, insoles that corrected 70% of it reduced back pain by 2.6 points out of 10 more than insoles that didn't, with fewer days off sick. In 33 people with differences of 10 mm or less, correcting inserts reduced pain and disability over about 10 weeks. But a review of 10 studies, only 1 of them randomised, called the evidence low quality and found no agreed threshold for when a lift is worth it.

Sources 14, 24, 15, 25

Side-hip training and the pelvis droppingEmerging evidence

In 40 runners with shin pain, adding 4 side-hip exercises (the hip hitch, single-leg bridges, side-lying leg raises with the hip turned slightly in, and side-on step-ups), 3 sets of 15, 3 times a week for 8 weeks, reduced how far the pelvis dropped by about 50%, against 19% in runners who didn't add them. The researcher who ran the trial wasn't blinded.

Source 11

Gluteal control training and a functional tiltEmerging evidence

In 48 people with back pain and a functional leg length difference, 6 weeks of gluteal control training reduced the measured tilt from about 2.9 to 1.0 degrees, the functional difference from 0.9 to 0.3 cm, and pain, more than regular trunk exercise. It's one small trial, measured by hand, with heat and traction given to both groups and no follow-up after 6 weeks.

Source 12

The exercises that work the side hip hardestEmerging evidence

In a meta-analysis of 56 EMG (electromyography, which records muscle activity) studies, the hip hitch worked all parts of the gluteus medius hard. Side-lying leg raises with the hip turned slightly in, single-leg bridges, side-on step-ups, standing leg raises against a band and banded side-steps worked its middle part hard. These studies measure muscle activity, not results.

Source 13

Strength alone may not change movementMixed evidence

Injured runners showed more pelvic drop than healthy runners in one comparison, but a review of 19 studies found no consistent link between hip strength and running mechanics, and in healthy people the Trendelenburg test didn't match hip strength. Train strength and control together.

Sources 26, 27, 28

Using side-hip training for a lateral tiltEmerging evidence

No trial has tested side-hip training for a lateral tilt in people without pain. Recommending it here is our inference from one small runners' trial, whose lead researcher wasn't blinded, one small back pain trial and muscle activity studies.

Sources 11, 12, 13

If one leg is shorter

Have the difference measured before you buy a lift. For differences under 2 cm, a small lift in one shoe is a cheap thing to try and easy to stop; the best trial corrected 70% of the difference. Children with larger differences are assessed by a specialist, and while they're still growing, surgery to slow growth in the longer leg is an option.

Sources 3, 14, 15

Train the side hips, both sides

The trials trained 3 times a week for 6 to 8 weeks: 3 sets of 15 in the runners' trial, and 10 holds of 10 seconds in the back pain trial. Start with 2 sets of 10, or with the wall-press holds if your outer hip is sore, and train both sides the same (our editorial starting point).

Sources 11, 12

The hip hitch

Stand side-on on a low step with one foot hanging off the edge, let that side of the pelvis drop a few centimetres, then lift it back up using the side hip of the standing leg, keeping both knees straight. Hold a rail. It has its own move page with written steps, but no 3D demo.

Sources 13, 11

Stiffness

Side bends, such as the overhead side bend and the Pilates mermaid, can ease a stiff side. They're for comfort and don't level the pelvis (editorial).

Children: see a GP if

Get it checked if:

• A child stands with one hip higher or one knee bent, walks on tiptoe on one side, limps or tires easily, or the difference seems to be growing.
• There are signs of scoliosis: a shoulder blade or hip that sticks out, ribs that stick out on one side, or clothes that don't hang evenly.
• A child has a limp with no obvious cause.

Sources 3, 29, 30

Children: get help straight away

Call 999 or go to A&E if a child gets sudden pain in the hip, knee or thigh, can't put any weight on a leg, has a leg that has changed shape or points at an odd angle, feels unwell with a high temperature or hot, cold and shivery, has severe pain low in the tummy as well, or is getting worse.

Source 29

Adults: see a GP if

A tilt or limp is new or getting worse, or one leg seems to have become shorter. After a hip replacement, if a leg feels longer or shorter, talk to your surgical team. See a GP about back pain that:

• Doesn't improve after a few weeks of looking after it at home, stops you doing day-to-day activities, or worries you.
• Comes with weight loss you can't explain, a lump or swelling in your back, or a change in the shape of your back.
• Doesn't improve with rest, is worse at night, or is worse when you sneeze, cough or poo.
• Is coming from the top of your back (between your shoulders), rather than your lower back.

Sources 31, 32

Hip pain: see a GP if

Hip pain is stopping you doing normal activities or affecting your sleep, is getting worse or keeps coming back, hasn't improved after 2 weeks of looking after it at home, or your hip is stiff for more than 30 minutes after waking up.

Source 32

Back pain: call 999 or go to A&E if you have

Back pain with any of these:

• Pain, tingling, weakness or numbness in both legs.
• Loss of feeling around your genitals or anus.
• Changes in your bladder or bowels, such as difficulty peeing, or peeing or pooing yourself.
• Changes in how your penis or vagina feels during sex, not being able to get or keep an erection, or not being able to orgasm.
• Chest pain.
• Back pain that started after a serious accident, such as a car crash.

Source 31

Back pain: urgent GP appointment or NHS 111 if

You have back pain and:

• You feel hot, cold, shivery or generally unwell.
• The pain is severe, started suddenly or is getting worse quickly.

Source 31

Hip pain: urgent help

Call 999 or go to A&E for severe hip pain after a fall or injury, if you can't walk or put weight on the leg, or for tingling or loss of feeling in the hip or leg after an injury. Ask for an urgent GP appointment or get help from NHS 111 for severe hip pain that started suddenly without a fall, a swollen hip that feels hot, a change in skin colour around the hip, or hip pain with a high temperature and feeling unwell.

Source 32

"A tilted pelvis must be fixed to stop back pain."Strong evidence

In the general population, small leg length differences and pelvic asymmetry aren't linked with back pain. People who stand all day with a measured difference of 6 mm or more may be an exception.

Sources 2, 7, 8, 9, 10

"The lower hip has the weaker muscles."Emerging evidence

There's no evidence for this. A lower hip often reflects a shorter leg, and in healthy people the pelvis dropping didn't match hip strength. Train both sides the same.

Sources 2, 28

"You can tell which leg is shorter in the mirror."Emerging evidence

Hip height doesn't reliably show which leg is shorter or by how much, and even trained hands miss the difference by 4 to 5 mm.

Sources 2, 6

"Exercise can level any pelvis."Emerging evidence

It can't change bone length or a structural scoliosis. One small trial found that training reduced a functional tilt.

Sources 3, 12

"Everyone with a leg length difference needs a heel lift."Mixed evidence

Most people have a small difference, and differences under 2 cm usually cause no problems. Lifts help some people, but the evidence is low quality and there's no agreed threshold.

Sources 2, 3, 15

"A leg length difference causes scoliosis."Emerging evidence

A tilted pelvis can produce a curve that straightens when the pelvis is levelled, but a leg length difference hasn't been shown to make a true scoliosis worse.

Sources 5, 18