Sagittal movements of the human lumbar vertebral column: a quantitative study of the role of the posterior vertebral elements.

The influence of the posterior vertebral ligamentous and bony elements on the sagittal range of motion of the lumbar spine has been investigated by observing the effects of sectioning ligaments and pedicles in 17 cadavers of both sexes with an age range from 14 to 78 years. The main investigation showed that the apophyseal joints provide a greater restraint to flexion and extension movements than do the lumbar ligaments. It also showed that the age changes which most severely affect movement in elderly persons occur in the intervertebral discs rather than in the posterior elements.