Can Quadratus Lumborum Be a Lateral-Flexor of Lumbar Spine?
Anatomically, quadratus lumborum originates from iliac crest and inserted into the transverse processes of lumbar vertebrae and twelfth rib. From the point of biomechanics, it has been presented as side-flexor (lateral flexor) of spine. In this article, we shall analyze the possibilities of lateral flexion of lumbar spine taking their facet orientation seriously into account. There has been a wide range of studies related to the plane of orientation of lumbar facets. But when compared to facets of thoracic spine, lumbar facets are more saggitally oriented. This sagittal plane orientation makes the lumbar spine more specialized for flexion and extension. (It should be noted at this point that the coronal plane orientation of facets of thoracic spine makes them more specialized for lateral flexion and transverse plane rotation as well). If the entire vertebral column is personified as a plant, then its root is sacrum which is deeply rooted between two innominate bones. The whole world of
