立位体幹前後屈時の腰椎矢状面椎間挙動解析

Motion Analysis of Sagittal Lumbar Segments During Trunk Flexion and Extension

　健常男性9名に対し，角度変化が中等度の立位体幹前後屈を行わせた際の矢状面腰椎挙動をX線シネ撮影装置で撮影し，各椎間の角度変化および位相差を椎間別に比較した．その結果，前屈動作において，L2/3の角度変化がL4/5に比べ有意に大きく，L1/2およびL2/3がL4/5に比べ有意に早く挙動を開始した．一方，後屈動作では角度変化，位相差ともに有意差は認められなかった．以上から，角度変化が中等度の前屈動作ではL2/3の角度変化が大きく，上位椎間から挙動を開始することが明らかとなった．

　Sagittal images of the lumbar spine of nine healthy males were continuously recorded by cineradiography during trunk flexion and extension. The angular displacement and the phase lag at each segment (L1/2, L2/3, L3/4, L4/5) were compared between lumbar segments in both flexion and extension. In flexion, the angular displacement at L2/3 was significantly greater than at L4/5, and motion started significantly earlier at L1/2 and L2/3 than at L4/5. By contrast, there were no significant differences in angular displacement or phase lag between the lumbar segments in extension. These results revealed greater angular displacement at L2/3 and that lumbar segmental motion starts at the upper segment in moderate flexion.