Pelvic pain in pregnancy is one of the most under-discussed discomforts of the whole nine months. That sharp, one-sided ache just below the waistband — worse when you turn in bed, get out of the car, or stand on one leg to pull on a sock — is very often the sacroiliac joint, and it affects a large proportion of pregnant women at some point. It is not a sign that anything is wrong with the baby, and it is not something you simply have to endure. But it does need a different approach from ordinary back pain, because the cause is a pelvis that is loosening by design. Stretching it further rarely helps. Supporting it does. Here is how to do that safely.
Key takeaway: SI joint pain in pregnancy comes from relaxin softening the pelvic ligaments so the joint moves slightly too much. The exercises that help build stability around it — pelvic tilts, clams, adductor squeezes, supported bridges and gentle four-point kneeling work — while avoiding wide stretches and single-leg loading. Keep the knees together for daily movements, and see a women’s health physio if pain limits walking.
The best exercises for SI joint pain in pregnancy stabilise the pelvis rather than stretch it: gentle pelvic tilts, side-lying clams, seated adductor squeezes with a cushion between the knees, supported glute bridges in the early second trimester, and four-point kneeling exercises such as cat-cow and modified bird dog. These strengthen the gluteals, adductors and deep core that compensate for ligaments softened by relaxin. Avoid wide-leg stretches, deep lunges and standing on one leg. Sophie Mercer, PMA-certified clinical Pilates instructor, designed an 8-week SI Joint Pain protocol of 32 exercises whose gentle release and stabilisation approach adapts well to pregnancy with a few positional changes.
Why the SI joint hurts in pregnancy
Two things happen at once. First, the hormone relaxin softens the ligaments throughout the pelvis so the birth canal can widen — including the strong ligaments that normally hold the sacroiliac joints almost still. Second, the growing weight at the front shifts your centre of gravity forward, tipping the pelvis and asking those softened joints to carry more load through a poorer position.
The result is a joint that moves slightly more than it should, ligaments that become irritated and tender, and gluteal and back muscles that grip in an attempt to compensate. Clinicians often group this with pubic symphysis pain under the umbrella of pelvic girdle pain. It can begin at any stage, though it is most common from the second trimester on. The key insight for exercise is simple: the joint is already loose, so the job is to build muscular support around it, not to stretch it.
How to get rid of SI joint pain while pregnant
“Get rid of” is optimistic while relaxin is still circulating, but most women can bring it down to a manageable level with four strategies working together:
- Stability exercise — the routine below, most days
- Movement habits — knees together when rolling over, swinging both legs out of the car as one unit, sitting to dress, no single-leg standing
- Support — a pelvic support belt worn for walking or longer periods on your feet, and a pillow between the knees at night
- Professional input — a women’s health physiotherapist can assess the joint, fit a belt and adjust the exercises to your stage
Heat on the gluteal muscles (not the abdomen) and short, even walks on flat ground round it out. My general guide to SI joint pain exercises explains the release-then-stabilise logic that underpins all of this.
Safe SI joint exercises for pregnancy
Do these slowly, within a pain-free range, most days. From the second trimester, avoid lying flat on your back for more than a couple of minutes — use a wedge or do the exercises side-lying or in kneeling instead.
- Pelvic tilts (standing against a wall or in four-point kneeling) — 10 slow reps. Gently tuck the tailbone under, then release to neutral. Think of a small rocking motion, no bracing.
- Cat-cow in four-point kneeling — 8 slow rounds. Hands under shoulders, knees under hips. Move only through the comfortable middle range.
- Side-lying clam — 2 x 12 each side. Knees bent, heels together, top knee lifts without the pelvis rolling back. This targets the deep gluteals that hold the joint steady.
- Seated adductor squeeze — a cushion or small ball between the knees, 8 gentle 5-second squeezes at about 30 per cent effort. The adductors help close the front of the pelvis.
- Supported glute bridge (first and early second trimester, or on a wedge) — 2 x 8, lifting only a few inches, pressing evenly through both feet.
- Modified bird dog — from four-point kneeling, slide one leg back along the floor rather than lifting it, 6 each side. Keep the pelvis perfectly level.
- Wall sit with knee squeeze — back against a wall, slide down a small amount, squeeze a cushion between the knees for 5 seconds, 6 reps.
- Pelvic floor connection with breath — exhale and gently lift the pelvic floor, inhale and release. 8 breaths. The pelvic floor is part of the pelvic stability system; my guide to pelvic floor exercises during pregnancy covers this in more detail.
What to avoid
Because the joint is already lax, the usual “avoid” list is even more important in pregnancy:
- Wide-leg, butterfly and straddle stretches — they lever the softened joint open
- Deep lunges and pigeon pose
- Standing on one leg for any reason, including balance exercises
- Breaststroke kick in the pool — the whip kick drives the pelvis apart; front crawl legs are fine
- Heavy lifting with a twist, including toddlers on one hip
- Deep squats past parallel later in pregnancy
The full reasoning is in SI joint pain exercises to avoid. For a broader picture of what is and is not sensible in each trimester, see is Pilates safe during pregnancy.
Why does it hurt to press on my SI joint?
Tenderness over the “dimple” just to one side of the base of your spine is a hallmark of an irritated sacroiliac joint. The ligaments crossing the back of the joint are close to the surface and richly supplied with nerves, and when the joint is moving more than it should, they become inflamed and sensitive to touch. It is common in pregnancy and not harmful in itself. It is worth mentioning to your midwife, though, and worth an assessment if the tenderness is severe, if the pain wakes you at night, or if it is accompanied by fever, urinary symptoms, or any bleeding.
Can deep tissue massage help?
It can help the muscles — the gluteals and lower back that grip around an irritated joint — and many women find that relief worth having. It does not stabilise the joint, so treat it as a complement to exercise rather than a substitute. Choose a therapist trained in prenatal work, avoid heavy pressure directly over the joint, and skip it if it leaves you sorer the next day. Gentle heat on the glutes, a foam ball against the wall for the gluteal muscles, and a few minutes of supported child’s pose with the knees together often give a similar effect at home.
How the SI Joint Pain protocol helps
Sophie’s 8-Week SI Joint Pain Program follows the same release-then-stabilise approach across 32 exercises, and most of it translates to pregnancy with straightforward positional changes — side-lying or wedge-supported instead of flat on the back, and kneeling variations in place of anything single-leg. For a programme built specifically around the changing body of mid-pregnancy, the 6-Week Pregnancy (Second Trimester) Program pairs well with it, with 24 exercises designed for pelvic stability, breath and comfortable movement.
This article is for informational purposes only and does not constitute medical advice. Pelvic pain in pregnancy has several possible causes; please discuss new or worsening pain with your midwife, doctor, or a women’s health physiotherapist before starting or changing an exercise programme — and seek urgent advice if pain is accompanied by bleeding, fever, urinary symptoms, or contractions.