Most stretches loosen the muscles holding the SI joint together. Sophie's protocol uses precise core compression to create internal symmetry and stability — the opposite approach, and the one that lasts.
After 14 months of stretching myself sideways for SI joint pain, the stability work was the missing piece. First time I've gone four weeks without a flare.
Clinical Evidence: Pilates reduces lower back pain by up to 72% (Asik et al, 2025 RCT). NICE recommends Pilates as a first-line treatment for chronic lower back pain before medication.
Many people with SI joint have related compensation patterns elsewhere in the spine. These comparisons walk through how Sophie's clinical Pilates protocols differ from generic stretching for each condition.
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The sacroiliac (SI) joint is a small, semi-fixed joint between the sacrum and the ilium of the pelvis. It is not designed to move much — perhaps two to four degrees in any direction. When the SI joint becomes painful, the problem is almost never that it is too stiff. The problem is that one or both sides have lost their normal stability and are micro-moving in ways the surrounding ligaments and nerve endings find threatening. Stretching the area, the most common first-line response, often makes this exact problem worse.
SI joint pain is a stability problem, not a flexibility problem. The joint has lost the muscular and ligamentous tension that holds it in its narrow safe zone of micro-movement. When you stretch the muscles that surround it — typically the hip flexors, glutes, piriformis, and the deep rotators — you reduce the very tension that the joint depends on to stay stable. Each stretch session feels productive in the moment because the surrounding muscles relax, but the SI joint becomes more vulnerable. Symptoms predictably return, often worse, within hours.
Single-leg stretching (figure-four, pigeon, lunging hip flexor stretches) is particularly counterproductive because it asymmetrically loads the SI joint while reducing the muscular tension that should be opposing that load. The joint shifts further out of its safe zone, the surrounding ligaments take the strain, and pain intensifies over the following day.
The third issue is one of motor control. The deep core muscles — transversus abdominis and the pelvic floor — provide what is called force closure of the SI joint. They tension the joint into stability through their attachment to the thoracolumbar fascia. In SI joint pain, this force closure system is almost always under-firing. Stretching does nothing to wake it back up. Stability cannot be stretched into existence.
A clinical Pilates protocol for SI joint pain rebuilds the stability system that the joint has lost. The work is precise and unfamiliar at first — most people have never consciously activated their transversus abdominis or pelvic floor before — but it is what the joint actually needs. The protocol systematically wakes up the deep stabilisers, layers in the gluteus medius (which controls pelvic side-to-side movement during walking), and integrates them into the daily movements where the SI joint is most often provoked: standing up, walking, getting in and out of cars, sitting for long periods.
Critically, the protocol avoids asymmetric loading in the early weeks. There are no single-leg movements, no deep lunges, no exaggerated forward folds, no aggressive hip stretches. Every movement in weeks 1–3 is bilateral and supports the joint while teaching the stabilisers to fire. This is the opposite of what most generic Pilates classes do — which is why people with SI pain often feel worse after a generic class.
By weeks 4–6, the deep stabilisers are firing reliably enough that asymmetric loading can be re-introduced safely. By weeks 6–8, single-leg balance, controlled lunging, and functional pelvic patterning rebuild the joint's ability to handle real life without flaring.
Sessions are 20–30 minutes, four times per week for the first three weeks (frequency matters here for stability re-patterning), then three times per week through week eight.
8-week progressive programme · 32 clinical exercises · Weekly schedules · Recovery tracker
“After 14 months of stretching myself sideways for SI joint pain, the stability work was the missing piece. First time I've gone four weeks without ...” — Hannah R., Edinburgh, UK · 4 weeks flare-free (After 6 weeks)
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