RSTInfluencing Diurnal Variation in Disc Hydration as a Treatment for Non-specific Low Back Pain

The purpose of the proposed study is to test the effect of an intervention technique that reduces trunk flexion upon rising, on the outcome measures of self-reported back pain and functional impairment in individuals with chronic or recurrent non-specific low back pain (LBP). The intervention is a self-administered and requires no medical intervention or drugs. The technique referred to as the restrained sitting treatment (RST), involves training in minimizing forward bending of the trunk immediately upon rising. The technique builds upon a previous randomized controlled study conducted and published by members of the research team. The underlying premise of RST exploits the natural diurnal pattern as the intervertebral discs (people are tallest when they first wake up). The discs are fully hydrated upon rising, disc internal hydrostatic pressures and external forces acting on surrounding soft tissues are greatest at this time, and these pressures and forces can increase significantly with trunk flexion. The RST technique utilizes a back support used in sitting during the first hour upon rising to minimize trunk flexion during this critical period as the intervertebral discs begins the diurnal cycle of fluid loss. The study will test the null hypothesis that there are no significant difference in outcome (LBP, work or social function/disability) between groups performing RST, the experimental group performing RST upon rising, the control group performing prior to going to bed.