Biomechanical Effects of Industrial Eccentric Exertions

工业偏心运动的生物力学效应

• 批准号: 6662663
• 负责人: ROBERT G RADWIN
• 金额: $ 18.06万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-30 至 2005-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6662663
• 关键词: arm; biomechanics; blood chemistry; clinical research; creatine kinase; ergonomics; human subject; industry; magnetic resonance imaging; mechanical pressure; muscle stress; musculoskeletal disorder; neuromuscular disorder; occupational hazard; occupational health /safety; occupational psychology; occupations; pain; repetitive motion injury; tendon injury; work site

DESCRIPTION: This research studies the effects of repetitive eccentric exertions in industrial power hand tool operation on biomechanical properties of muscle and tendon in order to better understand the etiology and prevention of work related musculoskeletal disorders. It is hypothesized that increased power tool reaction force and build-up time corresponds with greater changes in the dymanic characteristics of the upper limb. A laboratory-based experiment will define the short-term relationship between repetitive eccentric exertions (i.e. reaction force magnitude and build-up time) and upper limb properties (i.e. stiffness, viscous damping and inertial mass). Subjects will repetitively resist forearm supination against a motor for simulating eccentric exertion levels representative of pistol grip power hand tool operation. Peak torque levels and build-up time will be experimentally controlled. Forearm mechanical properties will be measured before and following a period of work. Mechanical parameters will be ascertained using a unique apparatus that models the forearm as a single degree-of-freedom dynamic mechanical system by measuring the angular displacement of a disturbance to a known mechanical system in free oscillation when the subject uses maximal effort to oppose its motion. Our preliminary data reveals that significant stiffness and inertial mass changes are observed when exercising eccentrically at similar intensity levels. Biochemical measures of blood creatine kinase (CK), and anatomical measures using T2 changes in an MRI of the forearms will be compared with biomechanical parameters prior to, and following repetitive eccentric exertions for a random subset of the subjects. Subjective discomfort will be assessed using a visual analog scale, and forearm edema and strength will also be measured. The second experiment will assess similar upper limb biomechanical properties for industrial workers who regularly perform repetitive eccentric exertions of varying intensity, build-up time and repetition rate in selected industrial jobs. Subjects will be recruited from tool operation jobs on a local automobile assembly line. This research can ultimately lead to better ergonomic interventions through quantitative power hand tool design guidelines and work practices based on understanding the damaging effects of exposure to specific levels of reaction force, build-up time and repetition, as well as providing new outcome measures for epidemiological studies.

描述：本研究研究工业电动手持工具操作中重复偏心用力对肌肉和肌腱生物力学特性的影响，以便更好地了解与工作相关的肌肉骨骼疾病的病因和预防。据推测，电动工具反作用力和建立时间的增加与上肢动力特性的更大变化相对应。基于实验室的实验将定义重复偏心作用（即反作用力大小​​和建立时间）与上肢特性（即刚度、粘性阻尼和惯性质量）之间的短期关系。受试者将反复抵抗电机的前臂旋后，以模拟代表手枪式握把电动手持工具操作的偏心用力水平。峰值扭矩水平和建立时间将通过实验进行控制。将在一段时间的工作之前和之后测量前臂的机械性能。将使用一种独特的装置来确定机械参数，该装置将前臂建模为单自由度动态机械系统，方法是测量当受试者使用最大努力来反对其运动时对自由振荡中已知机械系统的干扰的角位移。我们的初步数据表明，在相似强度水平下进行偏心运动时，会观察到显着的刚度和惯性质量变化。血肌酸激酶 (CK) 的生化测量以及使用前臂 MRI 中 T2 变化的解剖测量将与随机受试者子集重复偏心运动之前和之后的生物力学参数进行比较。将使用视觉模拟量表评估主观不适，还将测量前臂水肿和力量。第二个实验将评估产业工人的类似上肢生物力学特性，这些工人经常在选定的工业工作中进行不同强度、建立时间和重复率的重复性离心运动。受试者将从当地汽车装配线上的工具操作岗位中招募。这项研究最终可以通过定量电动手持工具设计指南和工作实践来实现更好的人体工程学干预措施，该指南和工作实践基于了解暴露于特定水平的反作用力、建立时间和重复的破坏性影响，并为流行病学提供新的结果衡量标准研究。