The Correlation Between Sagitta Curvature And Range Of Motion Of Lumbar And Degenerative Lumbar Instability

Purpose：To investigate the correlation between sagitta curvature and range of motion oflumbar and degenerative lumbar instability.Background：In the book “Clinical Biomechanics of the Spine”,White and Panjabi answer thequestion “What is abnormal translational, angulational, or rotational motion thatshould be considered abnormal?”.Their checklist for the diagnosis of clinicalinstability in the lumbar spine is widely used.As we all know,the spine stabilizingsysterm consist of three subsysterm:spinal column,spinal muscles, surrounding thespinal column, providing dynamic stability, and neural control unit evaluatinganddetermining the requirements for stability and coordinating the muscle response. So thedegenerative lumbar instability is a dynamic progress.And the following radiogaphiccriteria of lumbar instability is widely used：sagittal plane translation of4mm orsagittal plane rotation greater than15°on flextion and extention randiography.All ofthis is about the ajacent segment instability, so in this paper wo try to detect thechange of lumbar sagittal curvature ang range of motion during the progress of lumbardegeneration.Methods:109subjects ranging in age45-60were enrolled in this study.All of them weredivided into three groups:Group A:only with chronic low back pain(55subjects);Group B:with chronic low back pain and ajacent segment instability(24subjuects);Group C:nomal group without chronic low back pain(30subjects).Thecriteria was followed:①c honic low back pain more than three months without anytrauma or operation of lumbar;②sagittal plane translation of4mm or sagittal planerotation greater than15°on flextion and extention radiography of lumbar;③nomalpersons without chronic low back pain.All the subjects underwent the neutral andflextion-extention radiography tests,and the sagitta curvature and range of motion of lumbar were measured too.The software SPSS16.0was utilized to statisticallyanalyzed the results.Results:There was no statistically significant difference between the Group A and C inthe sagittal curvature(P>0.05),but the range of motion of Group Adecreased(P<0.05).Compared with Group A,the sagittal curvature of Group Bchanged significantly,and the range of motion had significant differance whencompared with Group C.Conclution:The degeneration of lumbar that result in instability is self-limited,and thesagittal curvature and range of motion of lumbar chaged with the degeneration to keepthe stability.These two parameters of lumbar is related to the degererative lumbarinstability,and they supply the helps to the diagnosis and treatment of the lumbarinstability.