[A comparative study of three-dimensional movements of lumbar spine in the old and the young people].

This article is aimed at the differences in lumbar vertebral three-dimensional movement and in stability between the old and the young people, and at the reasons which lead to the differences. Fifteen fresh adult male cadavers were divided into two groups: the young group, 20-30 years old, comprising 7 cases; the old group, 60-70 years old, 8 caes. Lumbar spine(L1-S1) was cut down. Three-dimensional movements under a loading system were measured by a compute system. The result showed that the range of the motion of the old group was lower than that of the young group. It suggests that the lumbar spine of the old people is more stable than that of the young people. This may be associated with the degeneration of the lumbar vertebra, which arouses biocompensatory changes, so the lumbar spine becomes re-stable.