Is Your Lower Back Pain Actually SI Joint Pain? How to Tell

By Dr. Zach Greenwade, DC, MS | Published: June 29th, 2026

Did you know that roughly 80% of people will experience lower back pain at some point in their lives? What many don’t realize is that a significant chunk of that pain doesn’t come from the spine itself, but from the Sacroiliac (SI) joint—where your pelvis connects to your spine.

If you’re tired of guessing what’s causing your back aches, you’re in the right place.

📺 Watch the full video walkthrough here:

3 Ways to Tell If Your Pain is From the SI Joint

It’s easy to confuse general lower back pain with SI joint dysfunction. To help you figure out what’s going on, Dr. Zach from Performance Sport & Spine in Redmond Washington, recommends using these three simple criteria:

Is the pain one-sided? SI joint pain is typically felt on just the right or the left side of your lower back/buttock, rarely both at once.
Is it below the beltline? If you put a belt on, SI joint pain is located below that line, deep in the glute or pelvic region. If it’s above the belt, it’s more likely a lumbar spine issue.
Does standing up make you wince? The pain is frequently provoked by transitioning from a seated position to standing. It also tends to flare up during long walks, stairs, vacuuming, getting in/out of a car, or rolling over in bed.

What Exactly is the SI Joint?

Your SI joint is one of the strongest and most stable joints in your entire body. You have two of them (left and right), and they connect your pelvis to your sacrum—the triangular bone at the base of your spine.

Think of the sacrum as the keystone of an arch; it bears the weight of your entire upper body and transfers that load safely down to your legs. Because it handles so much force, it is heavily reinforced by dense ligaments. When something goes wrong here, it accounts for an estimated 15% to 25% of all lower back pain cases.

Why Does It Start Hurting?

Your SI joint is heavily reinforced by dense ligaments to transfer load between your upper body and legs. However, injury or dysfunction generally occurs when the joint is subjected to a combination of axial loading (downward, vertical pressure) and rotational stress at the same time.

- Motor Vehicle Accidents: Sudden, high-impact force that violently drives axial load through the spine while the pelvis rotates.
- Direct Falls: Landing hard on one side of the hip or buttock, driving sudden vertical force and twisting stress directly into the joint.
- Repetitive Overuse: Activities like long-distance running that subject the pelvis to repetitive, cyclical axial loading and alternating pelvic rotation.
- Pregnancy: A unique combination of rapidly increasing weight (axial load), an arched lower back (increased lordosis), and hormonal changes like relaxin that cause ligament laxity, making the joint more susceptible to rotational stress.

The four most common situations that combine these specific forces include:

Motor Vehicle Accidents: Sudden, high-impact force that violently drives axial load through the spine while the pelvis rotates.
Direct Falls: Landing hard on one side of the hip or buttock, driving sudden vertical force and twisting stress directly into the joint.
Repetitive Overuse: Activities like long-distance running that subject the pelvis to repetitive, cyclical axial loading and alternating pelvic rotation.
Pregnancy: A unique combination of rapidly increasing weight (axial load), an arched lower back (increased lordosis), and hormonal changes like relaxin that cause ligament laxity, making the joint more susceptible to rotational stress.

Daily Activities That Aggravate the SI Joint

Because these same forces—axial loading and rotation—happen during normal daily movements, a flared-up SI joint is easily aggravated by:

Climbing Stairs: Stepping up forces one side of the pelvis to take your full body weight (axial load) while the other side drops, creating a sharp shearing or twisting motion.
Vacuuming or Mopping: Pushing and pulling against resistance while stepping forward forces the pelvis into repetitive, asymmetrical rotation.
Getting In and Out of a Car: Twisting your torso to swing your legs out of the door combines downward body weight with sudden pelvic rotation.
Rolling Over in Bed: To turn over, you have to twist your upper body while driving force through your legs, putting a direct rotational twist right through an un-stabilized SI joint.

The SI Joint Relief Routine: Stretches & Exercises

Because the SI joint is a major load-bearing transition zone, the goal of therapy is to mobilize the surrounding tight tissues and then stabilize the joint from all sides (front, back, left, and right).

1. Gentle Mobility Stretches

The Thumb-Press Rotation: Lie on your back with your knees bent. Locate the bony bump on the back of your hip (your PSIS) with your thumb. Gently rotate your knees to the opposite side while applying steady pressure with your thumb into that joint space to isolate the stretch.
Pillow Squeeze & Roll: Place a pillow or ball between your knees. Squeeze it gently and rotate your hips side-to-side as one solid unit. Keep your feet and knees perfectly aligned to target the SI joint rather than the hips.
Figure-4 Rockers: Cross one ankle over the opposite knee. Gently rock your legs side to side within a comfortable range of motion. Do not force the painful side to match the flexible side; work with what your body allows.

2. Core & Pelvic Stabilization Exercises

To build a “buffer” of strength around the joint, aim to hold these positions for 20 to 30 seconds, provided they don’t increase your pain:

The Back (Glute Bridge): Lie on your back, knees bent, and drive your hips up toward the ceiling.
The Inside (Ball Squeezes): Lie on your back with a ball between your knees and squeeze inward firmly to activate the adductors.
The Outside (Wall Clamshell/Leg Raise): Lie on your side with your painful side up. Press your top heel back against a wall and lift it up. Regression: Bend your knee slightly to make the movement easier.
The Front (Plank Progressions): Start with a knee plank hold, ensuring your core is locked in. Progress to a full toes-and-elbows plank as your strength improves.
Banded Fire Hydrants: On your hands and knees with a resistance band around your knees, kick one leg back at a 45-degree angle to fire up the deep gluteal stabilizers.

The 4-Level Squat Progression

Since standing up from a chair is a classic trigger for SI joint pain, rebuilding your squatting mechanics is essential. Move through these levels sequentially as your pain decreases and your strength improves:

Level	Exercise Name	How to Do It	Focus Tip
Level 1	Assisted Partial Squat	Hold onto a sturdy counter or chair. Squat down just a quarter of the way and push back up.	Use your arms as much as needed to deload your hips.
Level 2	Assisted Chair Squat	Use a dowel or broomstick for balance. Squat down until your butt touches a chair, then stand.	Place a cushion on the chair to reduce the depth if it hurts.
Level 3	Full Box Squat	Reach your arms out in front of you. Sit back onto the chair and drive up using only your legs.	Imagine “pushing the floor away.” Don’t use your lower back to pull yourself up.
Level 4	Light Goblet Squat	Hold a light weight (even 2 to 5 lbs) at your chest and complete a full, controlled squat.	Over-preparing your body with weight makes everyday bodyweight movements feel effortless.

Fact vs. Fiction: 4 Huge SI Joint Myths Debunked

❌ Myth 1: “Your SI joint slipped out of place.”

The Reality: Your SI joint only moves about 2 to 3 millimeters total. It is anatomically impossible for it to “slip” or “rotate” out of alignment without severe, high-energy trauma (like a major car crash). If an adjustment makes you feel better, it’s due to a neurophysiological pain-relief effect, not because a bone was physically shoved back into place. Vleeming et al. 1990, Vleeming et al. 2012, Sturesson et al. 1989

❌ Myth 2: “A clinician can diagnose your SI joint just by pressing on your back.”

The Reality: Everyone’s pelvic bones are naturally asymmetrical due to genetics. Feeling an unevenness on your back doesn’t mean something is broken or shifted. A real diagnosis requires a combination of your symptom history and specific orthopedic provocative tests. Laslett et al. 2005

The sacroiliac dysfunction and pain is associated with history of lower extremity sport related injuries | BMC Sports Science, Medicine and Rehabilitation | Springer Nature Link

❌ Myth 3: “SI joint pain is incredibly rare.”

The Reality: It makes up roughly 15-25% of lower back pain cases. It is often misdiagnosed as a disc bulge or arthritis, which is why seeing a provider who knows how to rule out the lumbar spine is so important. Cohen et al. 2005

❌ Myth 4: “Prolotherapy or injections are a permanent cure.”

The Reality: High-quality studies show prolotherapy offers very little long-term benefit compared to controls. Cortisone injections can provide short-term relief to help you start exercising, but they don’t fix the underlying stabilization issue. Vleeming et al. 2007

❌ Myth 5: “Adjustments physically realign a misaligned SI joint.”

The Reality: A landmark study by Tullberg et al. (1998) used precise 3D X-ray imaging to track the joint before and after manual manipulation. The results showed that the adjustments did not alter the position of the SI joint at all. While manipulation is excellent for short-term pain relief, it works by calming the nervous system and relaxing tight muscles—not by mechanically shifting your bones back into place.

When to Seek Deeper Medical Care

If you’ve been diligently doing your exercises and seeing no improvement, your pain might be stemming from inside the joint rather than the surrounding muscles. Conditions like systemic arthritis (such as Rheumatoid Arthritis) or infections require blood work and X-rays.

Furthermore, if you experience unyielding morning stiffness that takes 30 to 40 minutes to fade, you should be screened for Ankylosing Spondylitis—a genetic inflammatory condition that specifically targets the SI joint and carries a specific blood marker ( $HLA\text{-}B27$ ). Additionally, keep in mind that by the time we reach our 60s, the SI joint naturally tends to completely fuse on its own, meaning some mobility-based treatments will naturally become less effective.

Ready to Get Your Movement Back?

Don’t let pelvic or lower back pain keep you on the sidelines. If you want a customized, step-by-step recovery plan tailored precisely to your body, we are here to help. We offer evidence-based sports chiropractic care right here in Seattle, as well as virtual one-on-one personal coaching worldwide.

👉 [BOOK YOUR APPOINTMENT ONLINE HERE]

Frequently Asked Questions (FAQ)

Can I run with SI joint pain?

Repetitive, high-impact activities like running can aggravate an inflamed SI joint due to the constant axial loading. It is usually best to temporarily swap running for low-impact alternatives like cycling or swimming while you focus on building hip and pelvic stability.

How long does it take for an SI joint flare-up to heal?

With conservative care, targeted stretches, and stabilization exercises, many acute flare-ups begin to settle within 4 to 6 weeks. However, chronic cases or issues stemming from ligament laxity (like during pregnancy) may take longer to fully stabilize.

Why does sitting down feel okay but standing up hurts so much?

When you sit, your pelvis tilts and changes how load is distributed. The physical act of transitioning from sitting to standing forces the SI joint to instantly take on the weight of your torso while undergoing rotation, which easily triggers irritated ligaments.

If you are local to the Seattle Eastside area and need a tailored rehabilitation strategy, visit our clinic or reach out to our team:

📍 Address: 16770 NE 79th Street, Suite 100, Redmond, WA 98052
📞 Phone: 425-896-7151
🌐 Online Scheduling: Book an Appointment Here

About the Author

Dr. Greenwade, DC, MS is an evidence-based sports chiropractor, movement specialist, and the founder of Performance Sport & Spine, serving patients across the Eastside in Redmond and Seattle. Holding a Master of Science in sports medicine alongside a Doctorate of Chiropractic, Dr. Greenwade specializes in modern physical medicine, progressive loading, and active, movement-based recovery. The clinic’s mission is to help active individuals and office professionals resolve acute and chronic musculoskeletal conditions without unnecessary injections, medications, or surgeries.

References & Scientific Literature

Vleeming et al. 1990 Vleeming, A., Stoeckart, R., Volkers, A. C., & Snijders, C. J. (1990). Relation between form and force closure of the sacroiliac joint. Spine, 15(12), 1332-1335.
Vleeming et al. 2007 Vleeming, A., Albert, H. B., Östgaard, H. C., Sturesson, B., & Stuge, B. (2007). European guidelines for the diagnosis and treatment of pelvic girdle pain. European Spine Journal, 16(6), 794-819.
Vleeming et al. 2012 Vleeming, A., Schuenke, M. D., Masi, A. T., Carreiro, J. E., Danneels, L., & Willard, F. H. (2012). The sacroiliac joint: an overview of its anatomy, function and potential clinical implications. Journal of Anatomy, 221(6), 537-567.
Sturesson et al. 1989 Sturesson, B., Selvik, G., & Udén, A. (1989). Movements of the sacroiliac joints: a roentgen stereophotogrammetric analysis. Spine, 14(2), 162-165. (This is the landmark study proving the joint only moves 2–3 mm!)
Laslett et al. 2005 Laslett, M., Aprill, C. N., McDonald, B., & Young, S. B. (2005). Diagnosis of sacroiliac joint pain: validity of individual provocation tests and composites of tests. Manual Therapy, 10(3), 207-218. (The definitive study on the 5 cluster tests for SI joint diagnosis).
Cohen 2005 Cohen, S. P. (2005). Sacroiliac joint pain: a comprehensive review of anatomy, diagnosis, and treatment. Anesthesia & Analgesia, 101(5), 1440-1453. (The source for the 15% to 25% prevalence statistic).
Tullberg et al. 1998 Tullberg, T., Blomberg, S., Branth, B., & Johnsson, R. (1998). Manipulation does not alter the position of the sacroiliac joint: a roentgen stereophotogrammetric analysis. Spine, 23(10), 1124-1128.

Medical Disclaimer

Disclaimer: The information provided in this article, including text, graphics, images, and other material, is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider, such as a sports chiropractor, physical therapist, or medical doctor, with any questions you may have regarding a medical condition or treatment plan. Never disregard professional medical advice or delay seeking it because of something you have read on this website.