If you’ve never heard of your sacroiliac (SI) joints, that’s okay: Many people haven’t. But these joints, which link the pelvis to the lower spine, are absolutely crucial to your movement, stability, and comfort. 

And when these joints get irritated, it can trigger a condition called SI joint pain, which often presents as low back and butt pain. It can make walking, climbing stairs, sleeping, running — pretty much everything — uncomfortable. The most common effect it has on people, though, is how uncomfortable it can be to sit with SI joint pain.

But take heart: There’s a lot you can do to relieve SI joint pain. Here, learn more about SI joint pain — and find out how to feel better with tips from our Hinge Health physical therapists.

What Is Sacroiliac (SI) Joint Pain?

You have two SI joints, one on each side of the sacrum, which is the triangular bone that sits below your lumbar spine (low back), explains Samantha Charlotin, PT, DPT, a physical therapist at Hinge Health. The SI joints attach the sacrum to the hip bone (ilium) with the help of strong ligaments. They’re also supported by nearby muscles, including the erector spinae, psoas, quadratus lumborum, piriformis, abdominal obliques, gluteals, hamstrings, and pelvic floor muscles (levator ani and coccygeus).

The SI joints aren’t supposed to move very much. That’s because their main job is to transfer weight from the low back to the lower extremities while keeping you stable. In some cases, however, these joints become irritated or inflamed, which may lead to pain in the lower back. In fact, research has shown that up to 30% of reported low back pain may actually be related to the SI joints.

Symptoms of Sacroiliac (SI) Joint Pain

SI joint pain can present in a variety of ways, says Dr. Charlotin. Some symptoms include:

• Pain in the butt, or pain that starts in the low back and extends into the butt

• Discomfort that’s accompanied by pain in the low back

• Pain in the thigh (which may be referred pain that originates in the SI joint, says Dr. Charlotin)

If you have these symptoms, but are also experiencing numbness, tingling, or weakness in the legs, you may have a related condition called sciatica. One key difference, says Dr. Charlotin, is that with SI joint pain these symptoms usually stop before the knee. With sciatica, the numbness or weakness typically extends below the knee.

Common Causes of SI Joint Pain

Many factors can contribute to SI joint pain. No matter what’s causing the discomfort, there’s a lot you can do to feel better. Some possible causes include:

• Arthritis, including osteoarthritis as well as inflammatory forms of arthritis, such as axial spondyloarthritis (axSpA).

• Pregnancy. Hormonal changes and other daily life changes that may come with pregnancy, like poor sleep and higher levels of stress, may be associated with the SI joint becoming inflamed, says Dr. Charlotin.

• A genetic disorder, such as Ehlers-Danos syndrome, that causes the joints to be overly flexible.

• Injury. If you fall or otherwise injure your hip, it could set off an inflammatory response in that region of the body, says Dr. Charlotin.

• Doing too much too soon. SI joint pain that develops gradually is often due to repeatedly doing too much of an activity, or doing something that requires a lot of repetitive motion, without doing the right strengthening exercises to prepare your body for those activities. Going past your movement sweet spot can irritate the SI joint.

SI Joint Pain: A Hinge Health Perspective

SI joint pain that feeds into back pain can be challenging and inconvenient, especially when it persists or interferes with your daily activities. No matter how bad your back pain is, or how long it’s been going on, you can always do something to help improve it. And that usually starts with moving more. 

Although moving through SI joint and back pain can seem scary and uncomfortable, small changes to your habits can yield huge benefits. And you're in the right place to get support for dealing with it.

Treatment Options for SI Joint Pain

There are many things you can do to ease SI joint pain. The following tips from our Hinge Health physical therapists and medical doctors can provide relief for SI joint pain. 

• Ice or heat. It’s your choice and a matter of what makes you most comfortable, says Dr. Charlotin. That said, she typically recommends ice for acute SI injuries (like from a recent fall) and heat for a chronic problem, like arthritis.

• Maternity support belt. If you experience SI joint pain during pregnancy, a flexible band that sits under your belly can relieve some of the pressure and help to calm the low back and hips.

• Pillow placement. Whether you’re pregnant or not, an S-shaped pillow — or even a regular pillow strategically placed between your knees — can help many people achieve a more comfortable sleeping position.

• Activity modification. If you have SI joint pain, remaining active is important. Research has shown that exercise reduces pain and mobility issues related to this issue. But regular activities — like yoga, core-strengthening exercises, jogging, and even walking — might be too painful for many people to start. To stay active, you might have to change these activities a bit, by finding easier variations, taking breaks, or cutting the overall time you do these activities until the pain subsides.

Medication. If your SI joint pain is due to a type of inflammatory arthritis, such as axial spondyloarthritis, see a rheumatologist. Certain medications, known as disease-modifying anti-rheumatic drugs (DMARDs), are very effective in preventing your immune system from attacking your joints.

This strengthens the deep core muscles, which are essential for stabilizing the core which can take pressure off the SI joints.

While moving in general is often helpful for SI joint pain, a physical therapist can recommend specific exercises designed to reduce pain by strengthening surrounding muscles. These moves, recommended by Hinge Health physical therapists, are a great place to start.

The information contained in these videos is intended to be used for educational purposes only and does not constitute medical advice or treatment for any specific condition. Hinge Health is not your healthcare provider and is not responsible for any injury sustained or exacerbated by your use of or participation in these exercises. Please consult with your healthcare provider with any questions you may have about your medical condition or treatment.

PT Tip: Modify Movements, As Needed

If you’re experiencing high levels of pain with movement, you might look at some ways to modify exercises to make them less painful, like dropping the intensity, slowing your speed, adding rest breaks, or reducing the amount of time you do the activities temporarily. 

Dr. Charlotin also highlights another option that she often tries with her patients to temporarily change how they move due to pain. “When you’re walking, going up and down stairs, or getting in and out of a car or bathtub, try to keep the pelvis square and legs together rather than separating them a lot,” says Dr. Charlotin. “This is one of many options I might explore with my patients to see if it reduces their pain.” A physical therapist can explore this with you, as well as create a specific exercise routine to help you heal. You can see a physical therapist in person or use a program like Hinge Health to access a PT via telehealth/video visit.

How Hinge Health Can Help You

If you have joint or muscle pain that makes it hard to move, you can get the relief you’ve been looking for with Hinge Health’s online exercise therapy program. The best part: You don’t have to leave your home because our program is digital. That means you can easily get the care you need through our app, when and where it works for you.

Through our program, you’ll have access to therapeutic exercises and stretches for your condition. Additionally, you’ll have a personal care team to guide, support, and tailor our program to you. 

See if you qualify for Hinge Health and confirm free coverage through your employer or benefit plan here.

This article and its contents are provided for educational and informational purposes only and do not constitute medical advice or professional services specific to you or your medical condition.

References

1. Sacroiliac joints. (n.d.). Mayo Clinic. Retrieved from https://www.mayoclinic.org/diseases-conditions/sacroiliitis/multimedia/sacroiliac-joints/img-20005962 

2. Kiapour, A., Joukar, A., Elgafy, H., Erbulut, D. U., Agarwal, A. K., & Goel, V. K. (2020). Biomechanics of the Sacroiliac Joint: Anatomy, Function, Biomechanics, Sexual Dimorphism, and Causes of Pain. International Journal of Spine Surgery, 14(Suppl 1), S3–S13. doi:10.14444/6077

3. Sacroiliac Joint Dysfunction. (n.d.). Cedars-Sinai. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/s/sacroiliac-joint-dysfunction.html

4. Jurik, A. G. (2023). Diagnostics of Sacroiliac Joint Differentials to Axial Spondyloarthritis Changes by Magnetic Resonance Imaging. Journal of Clinical Medicine, 12(3), 1039. https://doi.org/10.3390/jcm12031039

5. Added, M. A. N., de Freitas, D. G., Kasawara, K. T., Martin, R. L., & Fukuda, T. Y. (2018). Strengthening The Gluteus Maximus In Subjects With Sacroiliac Dysfunction. International Journal of Sports Physical Therapy, 13(1), 114–120. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5808006/