Geometric measurements of the lumbar spine in Chinese men during trunk flexion.

Abstract

An analysis of the geometric data of the lumbar spine in Chinese men. Lateral radiographs were obtained of 16 men in the upright position to a trunk flexion of 90 degrees in 30 degrees increments. To establish reference data concerning the geometry of the lumbar spine for various degrees of trunk flexion. In previous studies, the morphometry and alignment of the lumbar spine have been investigated. Reports of systematic analyses of the lumbar spine in trunk flexion have lacked adequate radiographic data. Moreover, few studies have focused on measuring lumbar spine geometric data in Chinese individuals. A total of 67 landmarks on each radiograph were identified. They were marked by investigators and digitized using a HyperSpace digitizing system (V.17: Mira Imaging Inc., Salt Lake City, UT). The geometric configuration of the vertebrae and discs then was derived from the digitized points. The dimensions of the vertebrae and disc on the lumbar spine obtained in this study were similar to those of previous studies. The motion of the lumbosacral spine had the greatest contribution in trunk flexion, approximately 90% (i.e., rotating at the rate of 9 degrees for each 10 degrees of trunk flexion) when the trunk was flexed from 30 degrees to 60 degrees. After that, the hips were dominant in accomplishing the trunk flexion from 60 degrees to horizontal. This motion patterns may be useful for making clinical diagnoses of lumbar function in Chinese men. No obvious interracial differences were found in the geometric data found in this study, which suggests that morphometric data obtained from Caucasian individuals may be applied to Chinese patients for clinical purposes.