SI Joint Stretches: Gentle Relief for the Low Back and Pelvis
Gentle stretches often used for sacroiliac (SI) joint discomfort: knee-to-chest, figure-4, hip flexor and child's pose, plus what to avoid and when to get help.
By Ayoub Farid · · 2 min read
The sacroiliac (SI) joints connect the base of your spine to your pelvis, one on each side. SI joint discomfort is usually felt low in the back, just off center, sometimes into the buttock. It can come from pregnancy, uneven loading, injuries or simply stiffness in the surrounding muscles.
Because low back pain has many possible causes, a diagnosis matters. A physical therapist can tell whether your pain is SI-related and which movements suit you.
See a professional if
- Pain followed a fall or accident.
- Pain radiates down the leg with numbness or weakness.
- You are pregnant and pain is new or severe.
- Pain is worsening or lasting weeks.
Gentle stretches commonly used for SI discomfort
Keep everything gentle and symmetrical; stop anything that increases pain.
1. Single knee-to-chest
On your back, gently hug one knee. 30 seconds per side.
2. Double knee-to-chest
Hug both knees, rock gently side to side. 30–45 seconds.
3. Supine figure-4
Opens the glutes and piriformis, which attach near the SI joint. 30 seconds per side. See piriformis stretch.
4. Kneeling hip flexor stretch
Pad the knee, tuck the pelvis. 30 seconds per side. See hip flexor stretches.
5. Child's pose
Knees wide, hips back. 45 seconds. See child's pose.
6. Pelvic tilts
10 slow reps on your back.
Movements to be careful with
- Deep, asymmetrical stretches like intense pigeon pose.
- Standing on one leg for long periods.
- Strong twisting if it reproduces pain.
Stability helps too
SI discomfort often improves with strengthening: glute bridges, side-lying leg raises and gentle core work like dead bugs. Many clinicians combine stretching with these.
A 3-minute gentle routine
| Move | Time |
|---|---|
| Pelvic tilts | 30 s |
| Single knee-to-chest, each side | 30 s × 2 |
| Supine figure-4, each side | 30 s × 2 |
| Child's pose | 30 s |
Do it with Suppl
Suppl's Lower Back Relief routine includes knee-to-chest, supine twist, cat-cow, sphinx and pelvic tilts, and the Deep Hip Opener covers hip flexors and glutes. Use them once you know gentle stretching is right for you. See stretches for lower back pain.
Frequently asked questions
What does SI joint pain feel like?
Often a dull ache low in the back, just to one side, sometimes into the buttock.
Is stretching good for the SI joint?
Gentle stretching of surrounding muscles may help; strengthening is often important too.
Can pregnancy cause SI joint pain?
Yes, hormonal and postural changes can contribute. See stretching during pregnancy and talk to your midwife or doctor.
How long until SI discomfort improves?
It varies. A physical therapist can give you a realistic timeline.