The sacroiliac (SI) joints sit where the base of your spine meets your pelvis, one on each side, just below the dimples of your lower back. They’re built for stability, transferring load between your spine and legs with only a few millimetres of movement. When that finely tuned system goes wrong — the joint moving too much or too little, or one side loading more than the other — you get a distinctive low, one-sided back pain, often spilling into the buttock, that’s worse when you stand on one leg, climb stairs, or roll over in bed. The encouraging part is that SI joint pain responds very well to the right exercise, because the fix is largely about restoring balanced support around the pelvis.
Key takeaway: SI joint pain usually comes from the joint being either too stiff or too loose, with imbalanced muscles around the pelvis. The most effective approach pairs gentle release (knee-to-chest, figure-four stretch) with stabilising strength (glute bridges, clams, deep-core work). Favour symmetrical, controlled movements and avoid loading the pelvis unevenly while it settles.
The most effective SI joint pain exercises combine gentle release with pelvic stabilisation. For release, try single and double knee-to-chest, a supine figure-four glute stretch, and slow pelvic tilts. For stability — the part that creates lasting relief — use glute bridges, clams, and deep-core activation to support the joint evenly. Avoid asymmetric, end-range loading while it’s irritable. Sophie Mercer, PMA-certified clinical Pilates instructor, built an 8-week SI Joint Pain protocol of 32 exercises that release and then stabilise the pelvis in a structured progression.
What are the best exercises for SI joint pain?
SI joint pain has two sides to its treatment, and you usually need both.
Gentle release eases an irritated, stiff joint:
- Knee-to-chest, single then double, to gently mobilise the lower back and pelvis
- Supine figure-four stretch — ankle crossed over the opposite knee, drawing the thigh toward you — to release the glutes and piriformis that often grip around an unhappy SI joint
- Slow pelvic tilts to move the joint comfortably
Stabilising strength is what makes relief last:
- Glute bridges to build the gluteal support the pelvis depends on
- Clams to strengthen the deep hip muscles that hold the joint steady
- Deep-core activation to create a stable, supportive cylinder around the pelvis
Most people over-focus on stretching and skip the stability work — which is exactly why the relief doesn’t stick.
How do you release the SI joint?
Gentle is the operative word. The release exercises above, done slowly and within a comfortable range, ease the joint without forcing it. What you’re aiming for is relief of tension, not a dramatic “crack” or end-range push. For a lot of people, the most effective “release” is indirect: once the muscles around the pelvis are strong and balanced, the joint stops getting repeatedly irritated, and the gripping and tightness settle on their own.
What should you avoid?
While the joint is irritable, steer away from anything that loads the pelvis unevenly or pushes it to its limits:
- Deep lunges and wide-legged stretches that pull one side of the pelvis
- Twisting under load
- High-impact activity during a flare
- Everyday asymmetric habits — standing on one leg to get dressed, repeatedly crossing the same leg, carrying a bag on one shoulder
Favour symmetrical, controlled movements that load both sides of the pelvis evenly. As stability improves, you can reintroduce more varied movement.
Why it hurts — and why stability is the answer
SI joint pain almost always traces back to a problem of support. Weak or imbalanced muscles around the pelvis, the ligament laxity of pregnancy, or asymmetric loading from posture and habit leave the joint either moving too much or compensating with stiffness. Either way, the joint gets irritated. That’s why stabilising the pelvis — building even, reliable muscular support around it — is the heart of lasting relief, and why a programme that controls and strengthens the whole region works better than chasing the pain with stretches.
How the SI Joint Pain protocol helps
Sophie’s 8-Week SI Joint Pain Program follows exactly this logic — gentle release first to calm the joint, then progressive pelvic stabilisation to support it for good — across 32 exercises in a structured sequence. Rather than guessing which stretch might help today, you follow a plan built to settle the joint and keep it settled.
This article is for informational purposes only and does not constitute medical advice. Low back and pelvic pain can have several causes; if your pain is severe, radiates down the leg, or doesn’t improve, please consult a physiotherapist or doctor before continuing.