EFFECT OF LOAD ASYMMETRY ON INTERNAL LOADING OF TRUNK

载荷不对称对行李箱内部载荷的影响

• 批准号: 2277700
• 负责人: ALI SHEIKHZADEH
• 金额: $ 3.59万
• 依托单位: HOSPITAL FOR JOINT DISEASES ORTHO INST
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 1995-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2277700
• 关键词: back injury; body physical activity; body regions; computed axial tomography; disease /disorder proneness /risk; electromyography; human subject; injury prevention; male; muscle strength; muscle stress; muscle tension; neuromuscular function; occupational health /safety; posture; striated muscles; young adult human (21-34)

In industry, carrying and lifting objects asymmetrically is the rule rather than the exception. This situation is hazardous to the musculoskeletal system due to an increase in coactivation of the musculature and an increase of the forces on the spine. The aim of this study is to quantify the activities of ten trunk muscles by using the surface electromyography (EMG) during maximal and submaximal isometric exertion under pure and combined loading conditions of the trunk. Combined loading is defined as the vectorial sum of moments in the sagittal and transverse planes. These planes are selected based on their prevalence in industrial tasks and low back injuries. To calculate the effect of internal loading, the muscle parameters are calculated from CT-scan images of each individual participant and individual muscle forces are estimated using an EMG-driven model. The compression and shear forces are calculated under suggested conditions. The effects of planar exertion (pure exertion) and combined exertion on the patterns of trunk muscle recruitment and compression and shear forces will be compared. The primary hypotheses of this study are: 1) The peak EMG activity of trunk muscles will be higher during the maximal combined exertion than during pure maximal exertion. 2) The mean of RMS-EMG of the ten selected trunk muscles will change significantly with the orientation of the net resultant moments of the trunk. 3) The compression and shear forces will be changed significantly by the orientation of the resultant moment. The present study will provide a better understanding of the effect of asymmetrical lifting on mechanical and neuromuscular performance and on the risk of injury to the back.

在工业中，不对称地搬运和举起物体是一种规则 而不是例外。这种情况对 肌肉骨骼系统由于增加共激活的 肌肉和脊柱上的力量的增加。 这项研究的目的是量化10块躯干肌肉的活动。 用表面肌电信号(EMG)检测最大和次极大波 在纯载荷和联合载荷条件下的等长载荷作用 后备箱。组合荷载的定义为向量矩之和 矢状面和横面图。这些平面的选择依据是 他们在工业任务和腰部受伤中的流行程度。 为了计算内部负荷的影响，肌肉参数为 根据每个参与者的CT扫描图像进行计算，并 个体肌肉力量是使用肌电驱动的模型来估计的。这个 在建议的条件下，计算了压力和剪力。 平面运动(单纯运动)和联合运动对运动能力的影响 躯干肌肉的募集和压缩剪切力的模式 将会被比较。 这项研究的主要假设是： 1)运动后躯干肌电活动峰值较高 最大联合用力比单纯最大用力时大。 2)选取的10条躯干肌肉的均方根肌电均值将发生变化 与净合成力矩的方向显著相关 后备箱。 3)压力和剪力将显著改变。 合成力矩的方向。 这项研究将使我们更好地了解 不对称举重对机械和神经肌肉性能的影响 背部受伤的风险。

项目成果

Capability and recruitment patterns of trunk during isometric uniaxial and biaxial upright exertion.

等长单轴和双轴直立用力时躯干的能力和募集模式。

• DOI: 10.1016/j.clinbiomech.2007.11.017
• 发表时间: 2008
• 期刊: Clinical biomechanics (Bristol, Avon)
• 作者: Sheikhzadeh,Ali;Parnianpour,Mohamad;Nordin,Margareta
• 通讯作者: Nordin,Margareta