Pain guide · Back pain
The sacroiliac (SI) joints join the base of the spine to the pelvis, one on each side. SI joint pain is felt low in the back on one side, around the dimple at the back of the pelvis, sometimes into the buttock or the back of the thigh. It is common in pregnancy and after childbirth, after injuries, and with inflammatory arthritis.
The evidence here is thin, so this guide is modest: what can and can't be diagnosed, what the small trials suggest, and a plan built on strength around the pelvis.
Exercise is for pain that has been checked or is clearly mild and settling.
The European pelvic girdle pain guideline defines pelvic girdle pain as pain between the top of the back of the pelvis and the fold of the buttock, particularly near the SI joint. About 20% of pregnant women have it. The NHS describes pelvic pain in pregnancy at the pubic bone at the front, across the lower back or into the thighs, worse walking, on stairs, standing on one leg and turning in bed, and says it is not harmful to the baby.
A cluster of six pain provocation tests matched an anaesthetic injection into the joint reasonably well: three or more positive tests picked up 94% of people whose pain the injection confirmed and correctly cleared 78% of those whose pain it did not, and when none of the six reproduced familiar pain the SI joint could be ruled out. But in a review of 43 treatment trials, more than 95% did little or nothing to rule out pain coming from the lower spine first, which weakens their conclusions.
The European guideline does not recommend hands-on mobility tests for diagnosis, which is a good reason to drop the "your SI joint is out of place" story.
Buttock pain, waking in the second half of the night and improvement with movement, in someone whose back pain started before 45, are among NICE's reasons to refer to a rheumatologist for spondyloarthritis. See a GP if that sounds like you.
A review of 9 studies of low to average quality reported benefits from exercise, manipulation and kinesiology tape. In a 51-person trial comparing exercise, manipulation and both, everyone improved: manipulation was ahead at 6 weeks, exercise at 12 weeks, and there was no difference at 24 weeks. There was no untreated comparison group.
In 81 women with pelvic girdle pain after pregnancy, 20 weeks of physiotherapy focused on specific stabilising exercises gave lower pain and disability than physiotherapy without them, after treatment and at 1 year. At 2 years the differences persisted, but disappeared after adjusting for the 1-year scores. The European guideline recommends an individualised programme of specific stabilising exercises after pregnancy.
Exercise reduces how severe back and pelvic pain gets in pregnancy, on low to moderate quality evidence, though it may not stop it happening. The European guideline recommends individualised exercise during pregnancy.
The European guideline found no evidence for a pelvic belt as a treatment on its own, but says one may be tried for short periods to see if it eases symptoms. For low back pain in general, NICE says do not offer belts or corsets, and the WHO advises against routine use. A belt may ease pregnancy-related pelvic pain for some people for short periods; it isn't a treatment by itself.
The European guideline does not recommend SI joint fusion except in severe cases after injury, once other treatments have failed.
Source 1
Some discomfort during exercise is fine, and it does not mean you are doing damage: the WHO counts "hurt does not necessarily mean harm" among the messages people with back pain need. Aim for pain you would call mild to moderate, no more than about 5 out of 10. It should settle within an hour or so, and your back should be no worse the next morning. If it is worse, do less next time (fewer reps, a smaller range, a lighter load), not nothing.
Leg symptoms are the exception: stop or shrink any movement that sends pain, pins and needles or numbness further down your leg. If leg symptoms move back towards your spine, that is a good sign, even if your back aches a little more for a while.
If pain climbs day after day, or you notice any warning sign, stop and get it checked. The 5 out of 10 figure matches this site's other pain guides and has not been tested in a back pain trial; in trials of long-lasting muscle and joint pain, exercise that allowed some pain did no harm.
Start at the first stage. Each move opens a full guide with a 3D demo.
Weeks 0 to 2. Two or three sessions a week, plus walking. The doses are editorial starting points, built on the stabilising and strengthening work common to the trials.
3D demoTreadmill walkingBeginner · Cardio machine10 to 20 min · A comfortable pace and stride
Harder: Treadmill jogging
3D demoGlute bridgeBeginner · No equipment2 sets of 8 to 10, small range
Easier: Pelvic tilt into bridge · Harder: Glute kickback (quadruped hip extension)
3D demoHip Windshield WipersBeginner · No equipment10 slow passes, small range
Harder: 90/90 hip lift-off
3D demoLying adductor ball squeezeBeginner · Other / check instructions5 gentle holds of 5 to 10 s
Harder: Copenhagen plank
Move on when: These are comfortable, and the pain is no worse the next morning.
Weeks 2 to 6.
3D demoStaggered-stance bridge (offset bridge)Beginner · No equipment2 sets of 8 each side
Easier: Pelvic tilt into bridge · Harder: Glute kickback (quadruped hip extension)
3D demoBird dog, one limb at a timeBeginner · No equipment3 sets of 6 to 8 each side
Harder: Bird dog
3D demoBird dogBeginner · No equipment3 sets of 6 to 8 each side · Once one limb at a time is easy
Easier: Bird dog, one limb at a time · Harder: Bodyweight get-up
3D demoSide-lying leg raiseBeginner · No equipment2 to 3 sets of 10 each side
Easier: Lateral band walk · Harder: Lateral band walk, band at the feet
3D demoStep-upBeginner · A step2 to 3 sets of 8 each side · Once the low step is easy
Easier: Low step-up · Harder: Dumbbell step-up
3D demoHalf-kneeling Pallof pressBeginner · A band + An anchor point2 sets of 8 each side
Harder: Pallof press
Move on when: Stairs and standing on one leg are more comfortable.
From about week 6.
3D demoSingle-leg glute bridgeIntermediate · No equipment3 sets of 8 each side
Easier: Glute bridge · Harder: Alternate-leg bounding
3D demoSide plankIntermediate · No equipment3 holds of 20 to 30 s each side
Easier: Knee side plank · Harder: Side plank with leg lift
3D demoSplit squatIntermediate · No equipment3 sets of 8 each side
Easier: Bodyweight squat · Harder: Reverse lunge
3D demoSingle-leg Romanian deadliftAdvanced · A dumbbell3 sets of 6 to 8 each side · Hold a support at first
Easier: Dumbbell Romanian deadlift · Harder: Full Nordic curl
3D demoSuitcase carryIntermediate · A dumbbell + A kettlebell3 walks of 20 m each side
Easier: Farmer's carry · Harder: Overhead carry (waiter's walk)
3D demoLateral band walkBeginner · A band3 sets of 10 steps each way
Easier: Hip abduction machine · Harder: Lateral band walk, band at the feet
Move on when: Add load one change at a time while the pain stays settled.
| Habit or position | Why it matters | Instead |
|---|---|---|
| Standing on one leg to dress, or long one-sided standing | Loading one leg tends to aggravate pelvic girdle pain. | Sit to dress, and stand with your weight on both feet. |
| Big uneven steps, or getting out of a car with the knees apart | The same one-sided load. | Keep your knees together getting in and out of a car. |
| Turning in bed with the knees apart | The same one-sided load. | A pillow between your knees in bed, and keep the knees together as you roll. |
| Carrying a heavy bag on one side | An uneven load (an editorial precaution). | Split the load between two hands. |
| Being told to have it "put back in" again and again | Hands-on mobility tests aren't recommended for diagnosis, and there is no evidence the joint is "out". | Build strength around the pelvis. |
Hold 2 to 3 times for 20 to 30 seconds, a mild stretch, never sharp.
| Stretch | Reasonable for | Take care or skip | Why |
|---|---|---|---|
| Reclined figure four (eye of the needle, Sucirandhrasana) | Buttock tightness; SI joint pain if comfortable | Outer hip pain | Optional: 2 to 3 holds of 30 s if it eases pain. No trial shows it treats back pain, and most buttock pain is not the piriformis. |
| Hip Windshield Wipers | General stiffness, in a small range | A pinch in the groin | Gentle rotation that is easy to keep comfortable. |
| Supine spinal twist (Supta Matsyendrasana) | General stiffness | Its own guide flags SI joint and disc problems: skip it if it brings your pain on | Rotation with the knee pulled across the body. |
| Cat-cow | Most people, including in pregnancy | None within comfort | Moves gently through both directions. |
A 25-minute glute workout with bodyweight and a mini band: bridges, clamshells, band walks, kickbacks and lunges.
25 minBeginner9 movesA wall, A bandA 15-minute beginner core workout on the floor: dead bugs, bird dogs, knee planks, side planks and curl-ups.
15 minBeginner6 movesNo equipmentSI joint pain usually sits low on one side, around the dimple at the back of the pelvis, and can spread into the buttock or the back of the thigh. Sciatica is pain from an irritated nerve, felt down the leg and often into the foot, sometimes with tingling or numbness. Pain from the lower spine can be felt in the same places, so get leg symptoms assessed.
No trial has tested an avoid list. Based on NHS advice for pelvic girdle pain, limit one-sided loading for now: sit to dress, keep your knees together getting in and out of a car, and put a pillow between your knees in bed. Skip lying twists if they bring your pain on.
It may ease pregnancy-related pelvic pain for some people for short periods, and the European guideline says one can be tried that way. It isn't a treatment on its own, and for low back pain in general NICE says belts should not be offered.
There is no evidence that it does, and the European guideline does not recommend the hands-on tests said to find it. In one small trial, manipulation was ahead at 6 weeks, exercise at 12 weeks, and there was no difference by 24 weeks.
Usually, yes, at a comfortable pace and stride. The NHS advises staying active within comfort for pelvic girdle pain. Shorten your stride if long steps bring it on.
Pelvic girdle pain affects about 1 in 5 pregnant women and is not harmful to the baby. Stay active within comfort, keep your knees together getting in and out of a car, sit to dress, and talk to your GP or midwife if it is very bad. Exercise in pregnancy reduces how bad it gets. Back pain in the second or third trimester, or with fever, bleeding or pain when you pee, needs a same-day check.
Exercise education, not a diagnosis or treatment plan. It is written from the guidelines and studies listed above; review by a clinician is pending. If your pain follows an injury, is severe, is getting worse, or comes with any warning sign listed on this page, get it assessed. Health disclaimer.
