Lumbar Disc Bulges, the SI joint and the Iliolumbar Ligament

The iliolumbar ligaments are crucial in supporting the lower lumbar spine and they basically help stabilize the spine on the pelvis. They join the 4th and 5th lumbar vertebrae (L4 and L5) to the iliac crest at the back of the pelvis. The iliolumbar ligament is one of three vertebral-pelvic ligaments responsible for stabilizing the lumbo-sacral spine in the pelvis.

In the case of a disc bulge or rupture between the 4th and the 5th lumbar vertebrae or the 5th lumbar vertebrae and the sacrum (S1) or a combination of both, there is an increase in surface area (circumferential size) of the disc.  This leads to a reduction in height in the lower spinal column (especially between the wing of the L4 vertebrae and the iliac crest of the pelvis) and results in a loose upper band of the iliolumbar ligament (among other things including nerve root compression and sciatica).  When this band of the ligament becomes loose, there is a reduction of stability in the SI joint (where the tailbone joins the pelvis) and can result in the pelvis “being out” of alignment.

In my clinical experience I have found that in more than half of patients in which my clinical diagnosis reveals a lower lumbar disc bulge, there is a concurrent pelvic imbalance.  I have largely attributed this imbalance to a lax iliolumbar ligament due to the height reduction in the lower lumbar spine.  In the case of a pelvic imbalance (and associated muscle spasm… often of the hip flexors) one of the SI joints tends to be stiff.  This stiff SI joint can severely impede the effect of the McKenzie protocol that we utilize at Target for the treatment of disc bulges.  The stiff SI joint tends to cause a painful limitation in full lower lumbar extension which is paramount to the effectiveness of the McKenzie protocol.  The McKenzie technique, in my estimation requires re-alignment of the pelvis prior to the implementation and effectiveness of the technique.  I have found utilization of the more gentle (1) muscle energy techniques (2) contract-relax strategies and (3) trigger point release (especially for the hip flexors) and in some circumstances the more aggressive techniques of (4) isolytic stretching (5) acupuncture into the SI ligaments and (6) isolated lumbar gap manipulation to be particularly effective in re-aligning the pelvis.  Initial treatments involving both re-alignment followed by McKenzie are common in my practice until the McKenzie protocol (especially when combined with spinal decompression)  leads to some restoration of height in the lower lumbar spine in the case of the less extreme scenario of disc bulge through centralization of the nucleus of the disc.  When height is restored (and spastic imbalance about the pelvis is eliminated), the iliolumbar ligament becomes taught again and reduces the incidence of pelvic imbalances.  In some more complex cases, a sacro-iliac stabilization belt is used to maintain pelvic alignment.  
Lee Quenneville
Registered Physiotherapist
Orthopaedic acupuncturist

(A) Clin Biomech (Bristol, Avon). 2004 May;19(4):323-9.
(B) The influence of slouching and lumbar support on iliolumbar ligaments, intervertebral discs and sacroiliac joints. Snijders CJ1, Hermans PF, Niesing R, Spoor CW, Stoeckart R.
© Peter A. Fields, townsendletter.com/Jan2014/ortho0114.html