The first time I really understood the sacroiliac joint, I was watching a client try to stand up from my treatment table and quietly wince. She was a marathon runner, six months postpartum, and every time she loaded her right leg the pain shot into her buttock and refused to leave. Nothing on her scan explained it. Her hip was fine. Her disc was fine. Her SI joint, however, was doing exactly what SI joints do when the surrounding muscles stop holding them together properly — it was moving a fraction of a millimetre too much and screaming about it.
I see this pattern constantly. In my callanetics classes, in messages from runners, in my own body after a long orienteering weekend where I twisted through uneven Balkan terrain for six hours. SI joint pain is one of those problems that makes you feel broken when you are actually just under-supported. And the fix is almost always a combination of the right corrective exercises plus, during flare-ups, a little external input from a well-designed support.
Let me walk you through what I actually use.
What the SI joint is and why it destabilises
The sacroiliac joint sits where your sacrum (the triangular bone at the base of your spine) meets your ilium (the wing of your pelvis). You have one on each side. These joints barely move — a few millimetres of glide and a few degrees of rotation is all they should do — and their whole job is to transfer load between your spine and your legs.
They rely almost entirely on ligaments and surrounding muscles for stability. There is no big bony lock like your hip socket. That design works beautifully when the muscles around the pelvis — glutes, deep abdominals, pelvic floor, adductors — are doing their share. It falls apart quickly when they are not.
The four reasons I see SI joint pain most often:
Pregnancy and postpartum. Relaxin softens the ligaments to prepare for birth, and those ligaments can stay lax for months (sometimes over a year) after delivery. Add asymmetric load — carrying a baby on one hip, feeding on one side — and one SI joint starts taking more than its share.
Asymmetric sport. Runners who always run the same camber, golfers, tennis players, anyone who rotates predominantly to one side. Even orienteering does it if you consistently plant harder on one leg descending.
Prolonged sitting. Eight hours in a chair shortens hip flexors, switches off glutes, and lets the pelvis rock into positions the SI joint was never designed to hold under load. Then you stand up and go for a run.
Hypermobility. Some of us are just built loose. If you can hyperextend your elbows or touch your palms flat to the floor with ease, your SI joints probably need more muscular support than average.
The pain itself usually sits just below the dimples of your lower back, sometimes wrapping into the buttock or referring down the back of the thigh (which is why it gets confused with true sciatica or piriformis syndrome). It flares when you go from sitting to standing, roll over in bed, or stand on one leg to put your trousers on.
The 7 corrective exercises I use
These are the movements I give clients — and use myself when my right SI joint starts grumbling after a long race. Do them in this order. Two or three rounds, five days a week for the first six weeks.
1. Clamshells
Lie on your side, knees bent to about 45 degrees, heels stacked. Keep your heels together and open your top knee like a clamshell, without letting your pelvis rock backward. The moment your hips tilt, you have gone too far.
Why: Wakes up the gluteus medius, which is the single most important muscle for lateral pelvic stability. Weak glute med is my number-one finding in SI pain.
Dose: 2 sets of 15 per side.
2. Glute bridges with adductor squeeze
Lie on your back, knees bent, feet flat. Place a small ball, folded towel, or fist between your knees. Squeeze the ball gently and lift your hips into a bridge. Hold two seconds at the top.
Why: The adductor squeeze co-activates your inner thigh with your glutes. This combination compresses the SI joint from both sides — exactly the "force closure" the joint needs.
Dose: 2 sets of 12.
3. Bird-dog progressions
On all fours, extend opposite arm and opposite leg. Hold three seconds. The goal is to keep your pelvis so level that a glass of water on your lower back would not spill.
Progression: Once ten reps feel easy, add a slow elbow-to-knee tuck between reps.
Why: Trains anti-rotation through the trunk. SI joints hate uncontrolled rotation.
Dose: 8 per side.
4. Dead bug
Lie on your back, arms up, knees over hips. Lower opposite arm and leg slowly, keeping your lower back pressed into the floor. If your back arches, you have lost the pattern.
Why: Deep core control without spinal load. This is where you build the abdominal bracing that supports the SI joint in daily life.
Dose: 2 sets of 8 per side.
5. Single-leg balance
Stand on one leg for 30 seconds. Then close your eyes for 15 more. Then try it while brushing your teeth.
Why: Nearly every step of running is a single-leg balance moment. If you cannot control your pelvis standing still, you certainly cannot control it at mile ten.
Dose: Twice a day. Yes, really.
6. Hip hinge patterning
Feet hip-width, hands on hips. Push your hips back like you are closing a car door with your bottom. Knees stay soft. Return to standing by driving through your heels.
Why: Most SI flare-ups happen because people bend from their lower back instead of their hips. Retraining the hinge takes the load off the SI joint every time you pick something up.
Dose: 15 reps, daily.
7. Side plank variations
Start with a knees-down side plank, 20 seconds each side. Progress to a full side plank, then to a side plank with top-leg lift.
Why: The lateral chain — obliques, quadratus lumborum, glute med — wraps around and stabilises the pelvis from the side. Side planks train them all at once.
Dose: 3 holds per side.
When exercises alone are not enough
Here is the honest part. Corrective exercises rebuild the stability you have lost. But that rebuild takes six to twelve weeks, and during that window life does not pause. You still have to walk the kids to school. You still have that half marathon booked. You still have to sit through a four-hour flight.
During flare-ups, on long walk days, on your first few return-to-run sessions, the SI joint needs something the exercises cannot give you in real time: external compression. Wrapping the pelvis with a supportive belt gives the joint the "force closure" input it is missing while your muscles catch up. It is not a crutch. It is a bridge.
I explain it to my callanetics students like this: the belt is training wheels. You use it when you need it, you take it off when you do not, and eventually you need it less and less.
How HYKLE products fit into SI joint recovery
Deso and I designed our support gear specifically for people who do not want to stop moving. That is the whole point.
For SI joint flare-ups and the return-to-activity phase, the HYKLE Sciatica & Lower Back Support Brace is what I reach for first. The compression sits primarily around the hips and pelvis — which is exactly where an SI belt should sit, not up around the ribs like an old-school lumbar corset. Patricia, one of our customers, wrote about irritating her SI joint and struggling to sit at her desk for more than fifteen minutes: "I received the belt on a Friday and it was instant relief. By Saturday evening I was doing all my usual activities." That mechanism — pelvic-level compression, not abdominal — is the difference.
Alice, another customer, made a point I think about often: traditional wraparound braces that squeeze the upper abdomen can be genuinely uncomfortable if you have any blood pressure sensitivity. A hip-level SI support avoids that entirely.
For clients who spend long hours seated and notice their SI pain flares from postural collapse, I often pair the pelvic support with the HYKLE SpineFlex Posture Corrector. Not to force posture, but to remind the upper back what neutral feels like while the corrective exercises retrain the deeper muscles. Twenty to thirty minutes a day is plenty.
And for return-to-run days — the ones where you are anxious about whether the joint will hold — I recommend layering circulation support. A pair of HYKLE Compression Socks does not touch the SI joint directly, but it manages leg fatigue, and a less fatigued leg is a leg that lands better under a stable pelvis. Everything upstream benefits.
Runners doing longer efforts, or anyone standing on hard surfaces during recovery, also do well with the HYKLE Impact Pro insoles underfoot. Ground reaction force starts at the foot and travels up the chain — a better foot strike means less asymmetric input into the pelvis.
Practical implementation: the two-week starter plan
Here is how I would sequence it if you were starting today.
Week 1 — Calm and activate. Wear the pelvic support during your working hours and any walk longer than 20 minutes. Do exercises 1, 2, 4, and 5 daily. Skip running. Skip anything that spikes the pain above a 3 out of 10.
Week 2 — Add load control. Introduce exercises 3, 6, and 7. Reduce belt wear to just longer walks and any activity that historically flared you. Reintroduce short, flat walks without the belt to see how the joint responds.
Week 3 onwards — Load and progress. Belt only for higher-demand tasks: long hikes, first return runs, travel days. All seven exercises, three times per week minimum. Add walking hills before running hills.
Two rules I will not budge on:
If your pain is not trending downward after four weeks of consistent work, get seen. Persistent SI pain occasionally has other drivers — inflammatory conditions, referred hip pathology, or discs — and no belt in the world fixes those. My framework on restarting training after a setback has more on how I gauge that trajectory.
Getting back to what you love
The SI joint is not a fragile joint. It is a stability joint that has been asked to become a mobility joint by weak muscles, asymmetric habits, and prolonged sitting. Give it the corrective exercises and it will hold. Give it a little external support during the rebuild and the flare-ups, and you will keep training instead of shelving your season.
Everything at HYKLE is built for that in-between phase — the part where you are not injured enough to stop but not solid enough to ignore what your body is telling you. The HYKLE Sciatica & Lower Back Support Brace, the HYKLE Impact Pro insoles, and the HYKLE Compression Socks all live in that same philosophy: keep moving, support smartly, retrain patiently. That is how joints recover in real life. Every HYKLE product comes with our 90-day test-and-return guarantee, even if used — because we would rather you find out on your own body whether it works.