The Adult Spinal Column :: Biology, Tissues

short-changeUnderstanding the kinship amid repetitive lifting and the breakdown of platter tissue paper over several years of exposure is difcult to study in vivo and in vitro. The aim of this investigation was to develop an asymmetric Porovisco stretch nite divisor model of a lumbar motion segment that reects the biological properties and behaviors of in vivo disc Finite element predictions were compared to in vivo measurements published by Tyrrell et al. (1985) of percent change in total stature for two shipment protocols, short-term creep commitment and standing recovery and short-term cyclic loading with standing recovery. Future models will treat the tissues as poor-assume elastic and 3D in order to be more accurate and the relationship between repetitive lifting and disc degeneration TI.INTRODUCTIONhe adult spinal column is do up of 26 bones, called vertebrae 7 cervical in the neck, 12 thoracic in the rib area, 5 lumbar in the lower back, a sacrum and a coccyx. Loca ted between adjacent vertebrae are intervertebral discs. The human intervertebral disc acts as the bodys shock absorber to properly diffuse the stresses that the spine encounters. It is made up of the inner, gel-like nucleus pulposus and the show uper annulus fibrosus. Fluid flows through the disc in a diurnal cycle At the beginning of each day, the disc is fully hydrated, but as the day progresses, fluid is pressure to flow out of the disc this flow helps to carry nutrients into and waste out of the disc 1. The exploration of biomechanical properties of living tissues is fundamental to the analysis of structural doings of the musculoskeletal system. It is known that mechanical properties of living tissues are time dependent. Creep, relaxation, constant fund rate loading, and cyclic loading represent the various physiologic loading conditions that the human body confronts. For example, higher strain rates of loading can be used for simu lating vehicular accidents or trauma, medium strain rates of loading for daily activity, creep for the prolonged static posture, and cyclic loading for work in vibrating environments, i.