[Anatomic-functional viewpoints in treatment of injuries of the spine]

The ligaments of the lumbar motion segment acting together constitute primarily a holistic system responsible for every static and dynamic phase of segmental control. Taking into account the elastic tension produced by the intervertebral disks and the partial constraint imposed by the vertebral joints, the lumbar motion segment may be regarded as a particular form of ligamentous mechanism. Its fiber bundles, which are for the most part nonelastic, usually make a contribution to segmental movement, although the extent of their involvement depends upon how far that movement has progressed.