The disease appears to precede old age and to cause it. The spine becomes stiff first and old age follows. Therefore, we may say a man is as old as his spine, the arteries becoming hardened later from constant vaso-motor spasm, following sympathetic irritation.”(Nerve pressure) Sympathetic Segmental Disturbances The Evidences of the Association, in Dissected Cadavers, of Visceral Disease with Vertebral Deformities of the Same Sympathetic Segments Medical Times, November Lack of flexibility is a predictor of aging. Lack of flexibity in the hamstrings makes you 4 xs more likely to herniate your low back disc. Maintaining flexibility is important for normal spinal alignment and support.