Biomechanical experimental studies of the lumbar spine under static and dynamic loading conditions

During the past decades the number of spinal injuries has increased. Traffic accidents are the cause of more than 50 per cent of these injuries. Fractures and dislocations of the vertebrae as well as minor spinal injuries can cause both acute and chronic pain or disability. Knowledge of the biomechanical response of the spine under static and dynamic loads would lead to a better understanding of the injury mechanisms and to improved methods of prevention, diagnosis, and treatment. This information could also be useful to validate mechanical and mathematical models of the spine.
In this overview of the literature, biomechanical experimental methods and results for the lumbar spine under different loading conditions are presented and discussed. Numerous experimental studies on lumbar spine response and stability to static loads, especially in the physiological range of motion, have been reported in the literature, both for flexion, extension, lateral bending, compression and torsion. Most experiments are made on a single motion segment, consisting of two adjacent vertebrae, the disc and the surrounding ligaments.
A few studies have reported on the traumatic static, quasistatic and dynamic mechanical behaviour and the failure mechanisms of the lumbar spine, especially for flexion and compression. Some data is also available from dynamic loading of lumbar spine components (ligaments, bone, disc). Response and tolerance data for dynamic loads as well as for combined modes of impact are limited and the range of motion data are sparse.