Department of Biomedical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China.
Department of Biomedical Engineering, University of Miami, FL, USA.
J Biomech. 2022 Jun;139:111120. doi: 10.1016/j.jbiomech.2022.111120. Epub 2022 May 6.
The objective of this study was to quantitatively analyze the effect of lumbar spinal muscle atrophy on the compressive (perpendicular to the upper surface of the disc) and shear (parallel to the upper surface of the disc in the anterior-posterior direction) forces change on lumbar intervertebral discs using a full body musculoskeletal modeling approach. Muscles atrophy was modeled with reduction of the functional cross-sectional area (FCSA) of the muscles. Compressive and shear forces under two levels of lumbar muscle atrophy (20% and 40%) at eight daily postures (lying on back, seating slouched, seating straight, standing, standing flexed (36°), standing lift a 20 kg weight close to chest, standing lift a 20 kg weight flexed (38°), and standing lift a 20 kg weight with arm stretched) were analyzed. There was small increase in compressive forces on lumbar discs with muscle atrophy at most postures except lying and sitting straight. The maximum increase of compressive forces on lumbar discs were 23 N (6%), 28 N (5%), 34 N (2%), 71 N (6%), 89 N (4%), and 190 N (10%) with 20% atrophy, and 66 N (19%), 77 N (12%), 98 N (6%), 169 N (14%), 256 N (12%), 501 N (24%) with 40% atrophy at seating slouched, standing, standing flexed, standing lift close, standing lift flexed, and standing stretched arm, respectively. The shear force did not change significantly on lumbar discs with muscle atrophy. This study is important for understanding the biomechanical mechanisms of how lumbar muscle atrophy may affect the lumbar IVD health.
本研究旨在通过全身肌肉骨骼建模方法，定量分析腰椎脊柱肌肉萎缩对腰椎间盘压缩力（垂直于椎间盘上表面）和剪切力（平行于椎间盘前-后方向上表面）变化的影响。肌肉萎缩通过肌肉功能横截面积（FCSA）的减少来建模。分析了在 8 种日常姿势（仰卧、坐姿前屈、坐姿正直、站立、站立前屈 36°、站立提 20kg 靠近胸部、站立提 20kg 前屈 38°、站立提 20kg 时手臂伸直）下，腰椎肌肉萎缩 20%和 40%时的压缩力和剪切力。除仰卧和坐姿正直外，大多数姿势下腰椎间盘的压缩力随肌肉萎缩而略有增加。腰椎间盘的压缩力最大增加 23N（6%）、28N（5%）、34N（2%）、71N（6%）、89N（4%）和 190N（10%），在 20%的萎缩；最大增加 66N（19%）、77N（12%）、98N（6%）、169N（14%）、256N（12%）和 501N（24%），分别在坐姿前屈、站立、站立前屈、站立提重物靠近胸部、站立提重物前屈和站立伸直手臂时，肌肉萎缩 40%。腰椎间盘的剪切力随肌肉萎缩无明显变化。本研究对于理解腰椎肌肉萎缩如何影响腰椎 IVD 健康的生物力学机制具有重要意义。
