Sacroiliac Joint Pain

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Sacroiliac (SI) joint dysfunction is a frequent condition I address in clinical practice. The SI joint is a weight bearing joint that connects our sacrum to the ilium of the pelvis. The joint requires enough movement to allow load transfer between the spine, pelvis and legs, allowing us to advance our body through space with walking and running.
​Signs and symptoms of SI joint pain:

• low back pain on one side or both
• symptoms can worsen with transitions like sit to stand or lying down on the back
• pain aggravated by standing, walking, climbing stairs or running
• stiffness or reduced mobility in the low back or pelvis
• pain can be achey or sharp at the SI joint  or around the buttock
• pain can radiate into the groin, hip or down the leg

Interrelationships between the SI joint, the pelvic organs,  and the peripheral nerves

Since I have been studying the osteopathic based manual therapy work from the Barral Institute I have a greater appreciation for neural or visceral (organ) influences that may be contributing to pain in the  SI joint.
The relationship between SI joint pain and the pelvic organs is close and clinically important, not because the joint directly affects the organs, but because of shared anatomy, nerves and biomechanical connections.
The SI joints sit between the sacrum and the iliac bones of the pelvis.  They are:

• directly adjacent to the bladder, rectum, uterus, prostate
• connected by strong ligaments to the pelvic floor
• supplied by the sacral nerves that also contribute to the pelvic organ innervation

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Pudendal Nerve

SI joint irritation can cause referred pain

The SI joints are primarily innervated by the obturator and superior gluteal nerves, L4-S3 dorsal rami and branches of the sacral plexus. The same sacral nerve roots contribute to bladder and bowel function, uterine and pelvic floor sensation.  Because of this overlap of nerves, the SI joint can cause referred pain into the groin, the lower abdomen, the perineum, the rectum and the back of the thigh.  It can even mimic interstitial cystitis, endometriosis and prostatitis.  SI joint dysfunction can mimic pelvic organ pain and the opposite is also true: pelvic organ dysfunction can increase SI joint irritation.  For example, chronic bladder irritation may increase sacral nerve sensitivity or bowel inflammation could increase pelvic muscle guarding, which can both secondarily increase tension around the SI joint.

Biomechanical relationships and Hormonal Influences with Pregnancy/Postpartum

The SI joints helps transfer load between the spine and the pelvis.  When they becomes stiff or inflamed, pelvic alignment can shift, pelvic floor muscle tension can increase, and strain in the ligaments can occur.  If pelvic floor muscle guarding occurs it can lead to pain with intercourse, pain with bowel movements, bladder urgency or frequency. The pelvic floor attaches to the sacrum and coccyx, so chronic SI dysfunction often coexists with pelvic floor dysfunction.
It is also common to have SI joint issues during pregnancy and postpartum. Hormones relax the pelvic ligaments, increases joint mobility and the growing uterus changes weight distribution.

Big Picture

The SI joints and pelvic organs are anatomically adjacent, neurologically interconnected, biomechanically linked and clinically overlapping.  As a pelvic health specialist and general orthopedic physical therapist I can help you navigate the interrelationships that may be contributing to your pain.  I would love to support you.

Susan McLaughlin is a physical therapist who specializes in the management of pelvic floor and orthopedic dysfunctions. She is the owner of ALIGN integration|movement in Salt Lake City, UT.  Helpful tips and other self care strategies can be found at www.alignforhealth.com.