The SI joint can be a significant cause of lower back pain. Clinical publications have identified the SI joint as a pain generator in 15-30% of chronic lower back pain patients.1-4 In addition, the SI joint is a pain generator in up to 43% of patients with continued or new onset lower back pain after a lumbar fusion.5

Sacroiliac Joint (SI Joint) Anatomy

The sacroiliac joint (SI joint) is located in the pelvis; it links the iliac bones (pelvis) to the sacrum (lowest part of the spine above the tailbone). It is an essential component for energy transfer between the legs and the torso.

the si joint is the link between the ilium in the pelvis to the sacrum, the lowest part of the spine above the tailbone

Like any other joint in the body, the SI joint can be injured and/or undergo degeneration. When this happens, people can feel pain in their buttock and sometimes in the lower back, hips and legs. This is especially true while lifting, running, walking or even lying on the involved side.

It's common for pain from the SI joint to feel like disc or lower back pain, or sometimes hip or groin pain. For this reason, SI joint disorders should always be considered in lower back, hip, and pelvic pain diagnosis.

Some examples of symptoms related to the Si Joint:

  • Lower back pain
  • Sensation of low extremity: pain, numbness, tingling, weakness
  • Pelvis/buttock pain
  • Hip/groin pain
  • Feeling of leg instability (buckling, giving way)
  • Disturbed sleep patterns due to pain
  • Disturbed sitting patterns (unable to sit for long periods, sitting on one side)
  • Pain going from sitting to standing

Learn more about the treatments for conditions of the SI Joint click here.