Sacro-Iliac Joint Pain

Pain felt in the lower back, lateral hip area, groin or thighs

The Sacro-Iliac joints are small joints at the back of the pelvis, one on either side. They are formed by the connection of the sacrum and the right and left iliac bones. The sacrum is the large triangular shaped bone at the base of the spine, below the lumbar spine. The Iliac bones are the two large bones that make up the pelvis. As a result, the sacro-iliac joints connect the spine to the pelvis.

The sacro-iliac joints play a critical role in load transference between the lower limbs and the spine during gait, along with creating a stable base to allow efficient movement of the spine. As a consequence of the tightness of fibrous connections and the specific architecture of the sacro-iliac joint, mobility in the sacro-iliac joints is normally very limited but movement does occur.( Vleeming 2000)

Sacro-Iliac joint pain can be felt in the lower back, back of the hips, in the groin or in the thighs.
Sacro-iliac joint pain is most commonly related to pregnancy, childbirth, or trauma.

Trauma resulting in leg length discrepancy or poor lower limb biomechanics resulting in excessive movent in the sacro-iliac joints can also be the cause of pain referred from the sacro-iliac joints. This could be the cause of a patient's low back pain, groin pain, or postero-lateral hip pain.

If you have chronic low back pain that is not settling with treatment, then it is worth your while to have a thorough biomechanical assessment carried out to see if abnormal foot function is present or whether you might have a leg length discrepancy.

Siobhan Treacy MCSP, MISCP, FSOM
Chartered Physiotherapist
Walkwell Clinic