Trunk Muscle Coactivities During Axial Motion in Taiwanese Men Using the B-200 Isostation

李永輝(Yung-HuiLee) ； 郭承亮(Cheng-Lang Kuo) ； 曾永輝(Yang-Hwei Tsuang)

《Journal of Orthopaedic Surgery Taiwan》 16卷3期 (1999/09) Pp. 139-147

並列摘要

This study focused on the modeling of trunk musculature coactivational activities during the generation of axial torque. We recruited ten subjects and measured their isometric strength during trunk flexion, extension, lateral bend- ing (left and right), and rotation (left and right) on an Isostation B200. Musculature activities of eight functional units on both sides of the rectus abdo-minis (RAB-L and RAB-R), anterior abdominal oblique (AAO-L and AAO-R), latissimus dorsi (LAT-L and LAT-R), and erectus spinae (ERS-L and ERS-R) were collected simultaneously using surface electromyography.
The normalization electromyography of the eight trunk muscles differed as a function of motion directions. The most highly activated muscles (Prime movers) observed were the RAB-L and RAB-R in flexion, the ERS-L and ERS-R in extension; the AAO-L during left bending and the AAO-R during right bending; the LAT-L during left rotation and the LAT-R during right rotation. Prime movers were those of the ipsilateral muscles with an NEMG ranging from 40.0 to 46.7% MVC (Maxiaml Voluntary Contraction) (relative activation level ranging from 24.6 to 37.5%). There is also evidence that the synergist muscles have con-traction levels (ex: level B in flexion ranged from 32.6% to 12.3% MVC) that can not be neglected when calculating accurate forces. This can explain why optimization type biomechanical models which assume negligible cocontraction severely underestimate the mechanical loading of the spine.

並列關鍵字

Coactivation ； NEMG (normalization electromyography) ； RAL (relative activation level) ； MVC (Maximal Voluntary contrac-tion)