Increased lumbar spinal column laxity due to low-angle, low-load cyclic flexion may predispose to acute injury.

Lumbar spinal column laxity contributes to instability, increasing the risk of low back injury and pain. Until the laxity increase due to the cyclic loads of daily living can be quantified, the associated injury risk cannot be predicted clinically. This work cyclically loaded 5-vertebra lumbar motion segments (7 skeletally-mature cervine specimens, 5 osteoporotic human cadaver specimens) for 20 000 cycles of low-load low-angle (15°) flexion.