Sitting with Rotary Continuous Passive MotionBiomechanical Explanation of Health Effects

Abstract

Sitting with the use of a Rotary Continuous Passive Motion (RCPM) device seemed to be a promising technique for practical use with regard to spinal therapy and prevention.Spinal exercises and stimulation have been widely described to influence intervertebral disc nutrition, general flexibility and muscular health. Minor stimulation of only 1.0-degree cyclic rotation resulted in a remarkable physiological effect, expressed in a smaller amount of shrinkage during 1 hour of sitting compared to the conventional way of sitting.Intervertebral disc height is influenced by small axial rotation, even before facet joint interference. The cylindrical oriented annular fibers are stretched or slacked as a result of twisting, which is most common during daily life ambulation. Such stress-relaxation phenomenon occurs in the lumbar discs due to pelvic stimulation by means of Rotary Continuous Passive Motion, i.a. a motor driven seat pan moving in the horizontal plane.This RCPM response not only affects the intradiscal pressure changes, which are related to in- and outflux of nutrients by osmosis and diffusion, but forms also additional mechanical stiffening of the annulus fibrosis. This information may be of great importance for treatment and prevention of low back pain.