An In-Vitro Experiment to Study Sustained Torque on the Spine

In adolescent scoliosis patients, as the vicious cycle hypothesis proposed by Dr. Stokes suggests [1], a lateral spinal curvature produces asymmetrical loading of the skeletally immature spine, which in turn causes asymmetrical growth and therefore progressive wedging deformity. Numerous studies have been done to evaluate the effect of sustained compression or tension loading on the spinal bone growth [2,3]. However, in scoliosis patients, there is not only the asymmetrical axial loading which will worsen the curve progression, but also constant shear force in the transverse plane that may affect the bone growth. So far, no in vivo experiment has been done to study the effect of shear force on the spine. The goal of this study is to design an in vitro experiment that will provide incessant torques in the calves’ tails, and determine the relationship between the magnitude of the torque and change of stress between tail segments.