下腰疼痛的生物力学分析

A biomechanical analysis of low back pain

背景:下腰痛是人类极容易发生的疾病,原因复杂,发生机制依然不能完全阐明。目的:针对下背疼痛起因做一详细的力学分析。方法:藉由生物力学原理,应用计算软件Matlab与图像软件Photoshop对L4及两侧的小关节进行3D力学模拟。分析不同体质量的人在不同弯腰角度、提取不同重物时,L3-L4椎间盘所承受的滑脱力,以及在不同程度椎间盘退化的情形下,应力转移至关节囊的百分比。结果与结论:①L4因弯腰搬动物品时所受的压力会随着弯腰的角度增加而呈非线性递减,弯腰角度越大L4所受压力越小;当弯腰搬取物品时,L4所承受的压力与人体质量或物品质量呈正比;②当人弯腰达75°时,由于环状应力的产生可使腰大肌所承受的力可达体质量的20倍,来回反复做相同的动作就会使肌肉疲劳,进而对其造成损伤;椎间盘的退化也会将原先正常作用在周边组织的应力放大4倍左右,而对这些组织造成应力伤害。

BACKGROUND: Low back pain is a disease that is very easy to occur in human beings. The causes are complex, and the pathogenesis is still not fully elucidated. OBJECTIVE: To make a detailed mechanical analysis of the causes of lower back pain. METHODS: Based on the principle of biomechanics, the 3 D mechanical simulation of L4 and its small joints on both sides was carried out by using Matlab and Photoshop. The slip force of L3-L4 intervertebral disc when people with different body masses bend at different angles and extract different weights, and the percentage of stress transferred to the joint capsule in different degrees of disc degeneration were analyzed. RESULTS AND CONCLUSION:(1) The pressure on L4 when it bends to move the object can decrease nonlinearly with the increase of the bending angle. The greater the bending angle, the smaller the pressure on L4 is. When stooping to carry goods, the pressure on L4 is directly proportional to the mass of human body or goods.(2) When a person bends down to 75°, the strength of psoas major muscle can be 20 times of the body weight due to the generation of circular stress, and the same repeated action can make the muscle fatigue, and then cause damage. The degeneration of the intervertebral disc can enlarge the stress of the surrounding tissues by about four times, and cause stress injury to these tissues.