SI Joint Stretches and Exercises for Sacroiliac Joint Pain

01What

What is the SI joint?

The two sacroiliac joints link the sacrum, the triangular bone at the base of the spine, to the iliac bones of the pelvis. They are strong, stable joints with only a few degrees of movement, held tightly by ligaments. They transfer load between the spine and legs. Pain can come from the joint itself, its ligaments or inflammation (sacroiliitis). Studies suggest the SI joint is a source of pain in a meaningful minority of people with chronic low back pain.

02Symptoms

Symptoms of SI joint pain

• Pain on one side of the lower back, near the dimple above the buttock.
• Pain spreading to the buttock, groin or back of the thigh.
• Worse with standing on one leg, stairs, rolling in bed or getting out of a car.
• Worse after prolonged sitting or standing.
• Stiffness, especially in the morning with inflammatory causes.
• Pain usually does not go below the knee; if it does, a nerve cause is more likely; see sciatica stretches.

03Causes

Causes

• Pregnancy and after childbirth: hormonal ligament laxity and changes in posture.
• Falls or impact onto the buttock.
• Repetitive loading in running or one-sided sports.
• Leg length difference or abnormal walking patterns.
• Inflammatory arthritis, such as ankylosing spondylitis.
• Previous lumbar fusion surgery, which increases load on the SI joints.
• Degenerative changes with age.

04Stretches

SI joint stretches

• Knee-to-chest: lying on your back, bring one knee toward the chest, 20–30 seconds, then the other.
• Double knee-to-chest for gentle lower back stretch.
• Figure-four (piriformis) stretch: cross one ankle over the opposite knee and pull the thigh toward you, 30 seconds.
• Lower trunk rotation: knees bent, let them fall slowly to each side, 10 times.
• Child’s pose: kneel and sit back on the heels with arms forward, 30 seconds.
• Kneeling hip flexor stretch, 30 seconds each side; see tight hip flexors.
• Stretch to mild tension; avoid forceful positions that increase sharp pain.

05Strength

Strengthening exercises

• Glute bridge: 3 × 10–12, progressing to single-leg bridges.
• Clamshells: 3 × 15 each side.
• Adductor squeeze: squeeze a ball between the knees while lying with knees bent, 5 seconds, 10 times.
• Dead bug: slow alternating arm and leg movements with a stable trunk, 3 × 8 each side.
• Bird dog: on hands and knees, extend opposite arm and leg, 3 × 8 each side.
• Side plank from knees, 20–30 seconds.
• Exercise 3–4 times a week; aim for control rather than speed.

06Avoid

What to avoid during a flare

• Standing on one leg for long periods, such as when dressing.
• Heavy lifting with twisting.
• High-impact activities like running and jumping until pain settles.
• Sitting with legs crossed or weight shifted to one side.
• Deep lunges or very wide stances that strain the joint.
• Long periods without moving.

07Treatment

Other treatments

A sacroiliac (pelvic) belt can reduce pain during activity, particularly in pregnancy. Physical therapy may include manual therapy, exercise and movement retraining. Anti-inflammatory medicines can help short term if suitable. For persistent pain, image-guided injections of local anaesthetic and steroid into the joint can both diagnose and treat SI joint pain; radiofrequency denervation is an option for some people. Fusion surgery is reserved for carefully selected, severe cases. Inflammatory sacroiliitis is treated by a rheumatologist with specific medicines.

08Cases

Three common situations

• Pregnant woman with pain over the buttock when turning in bed: pelvic girdle pain is common; a pelvic belt, keeping knees together when turning and gentle exercises help.
• Runner with one-sided buttock pain after hill training: reduce hills, strengthen the glutes and progress gradually.
• Young man with morning stiffness that improves with exercise: ask a doctor about inflammatory back pain.

09Pregnancy

SI joint pain in pregnancy

Pelvic girdle pain, including SI joint pain, affects many pregnant women, often from the second trimester. Hormones such as relaxin loosen the pelvic ligaments, and the growing baby changes posture. Helpful strategies include keeping the knees together when turning in bed or getting out of a car, sitting to dress, taking smaller steps, avoiding standing on one leg, using a pillow between the knees at night and wearing a pelvic support belt. A physical therapist specialising in pregnancy can tailor exercises. Most women improve after birth, although some need ongoing support.

10Summary

Key points to remember

• SI joint pain is felt low in the back and buttock on one side.
• Gentle stretches and hip and core strengthening are the main treatment.
• Avoid prolonged one-leg standing and heavy twisting during flares.
• Belts, physical therapy and injections help persistent pain.