During movements that involve flexion, extension, and sidebending, the ligaments of the pelvis have very important roles stabilizing the hips and lumbar spine. One of these ligaments is the iliolumbar ligament. This ligament extends from the transverse process TP of the two lower lumbar vertebrae L4 L5 to attach to the iliac crest and blend with the interosseous ligaments of the SI. The role of this ligament is to restrict sidebending motion at the lumbosacral junction. This ligament is a prime suspect to low back pain. Remember: for every hour you sit, it takes 7- hours for these ligaments to regain their strength. As the ligaments weaken, they lose the ability to prevent the fifth lumbar vertebra from shifting forward on the sacrum, which may cause contralateral narrowing of the intervertebral foramen, facet arthrosis and possible sciatic nerve entrapment. In extreme cases, slippage of the fourth or fifth lumbar vertebra may result in spondylolisthesis.
One area for sciatic nerve occlusion lies beneath the anterior iliolumbar ligaments, which forms “fascial hoods” over the L4 and L5 nerve roots. The sciatic nerve must travel through these taut bands. In the image, you can see how an unbalanced hip could cause irritation of the sciatic nerve if the pelvis was rotated in one direction, or if the one ilium was anterior and the other could be posterior. During gait, this laxity would also cause the 4th and 5th lumbar vertebrae to be hypermobile and lead to non-neutral spinal mechanics at the lumbosacral junction.
With poor posture or trauma, nociceptive pain signals are sent to the cerebellum. What is one of the main functions of the cerebellum? The cerebellum receives information from the afferent nerves and the spinal cord and then regulates motor movements. In turn, with low back pain this would cause chemical cascades of histamines and things like that which would surround the tissue and cause irritation of sinovertebral and other nerves.
Obviously, the brain will try to stabilize the area, which would cause more compensation and other issues to look at. To treat these spasms that may occur in the low back, it’s important to make sure that you bring balance back to the hips and SI joint. Offer home corrective exercises to help keep the pelvis balanced and developing core/hip stability. In the video, you will see an easy way to scrub the iliolumbar ligament that helps relieve the irritation.