Experiment Study Of Biomechanics On Recovering Cervical Lordosis By Air-Cushion

Experiment Study of Biomechanics on Recovering Cervical Lordosis by Air-CushionMajor: Orthopaedics Traumatology of TCM Postgraduate: Yu Dandan Tutor: Prof. Wang HemingABSTRACTA method of 2-D finite unit calculation was setted up to study the distribution law of internal stress of cervical spine when three kinds of cervical radian pathological changes:smaller, straight, counterarch were treated by air-cushion used against the gravity action in nine cushion-laid places and two kinds of air-filled conditions.By investigating the relationship of stress and load-corresponding, the mechanism that air- cushion recovered cervical lordosis was probed into and suitable cushion-laid place was proposed.Pictured computer modles of three kinds of cervical radian pathological changes were setted up to deal with specific load-corresponding circumstances of different cushion-laid places and air-filled conditions according to coefficients of different cervical spine parts. Nodes and units of the models were differentiated and arranged automatically by the finite- division regular and shortest moment of force ruler. Through calculation of super SAP all data of load-corresponding and displacement of internal cervical spine can be achieved while cervical radian changed. The results showed: 1. Strain lie dat the front and rear edges of vertebrabodies and intervertebral discs.The forces at the front edge.s were stronger. The numerical value of load-corresponding to recover cervical radian at the level position was largest. Pressures at the rear edges of vertebra bodies and intervertebral discs and at the mean points of facet joints were largest too. The forces focused on the lower-mid cervical spine.That air-cushion recovering cervical radian and treating cervical spondylosis were verified. Level position was the most suitable place for cushion-laid.2. The rates of effect load-corresponding force indicated that rate of the smaller radian was higher than that of straight cervical spine which was higher than that of the counterarch cervical spine. It was easy for air-cushion to treat the smaller radian cervical spine and hard for the counterarch cervical spine.3.Though the effect load-corresponding forces of full-aired cushion were stronger slightly than those of half-aired cushion, that the latter with well-distribution made half-aired cushion suitable for lower-mid cervical spine which had the pathology changes and full-aired cushion was well for only mid cervical spine which had changes.The data of this study was significant and can provide guideline for the design and practical use of air-cushion which will ameliorate load-corresponding of cervical spine to recover cervical radian and largely improve the effecacy of the treatment of cervical spondylosis and reducing the morbility of cervical spondylosis.