人体日常活动机械功及能量效率的初步研究

Preliminary experiment of the mechanical work and energy efficiencies of daily physical activity

目的计算三种常见身体活动的机械功和功率,并与代谢测试舱测量的能量消耗值对比,以期得到一种计算人体机械功的新方法并进行日常活动机械功及能量使用效率的初步研究。方法利用基于多传感器的运动参数采集系统对一名健康受试者进行多个肢体的角速度测量。选取坐到站,坐姿时前后移动躯干,坐姿时一腿放另一腿上,三种简单的身体活动方式,利用拉格朗日方程对各个单项动作进行生物力学建模并利用测量的参数进行机械功的计算。同时利用间接能量代谢实验舱和便携式测试仪进行身体活动机械功和能量代谢的关联研究,确定这三种身体活动的能量使用效率。结果利用"关节功率法"计算的机械功率与能量代谢实验舱测得的能量代谢率高度相关(相关指数为0.975)。其中,坐到站、坐姿时前后移动躯干和抬腿三种活动的平均机械效率分别为27.1%、19.0%和18.3%。结论采用运动生物力学建模的方法分析日常身体活动,是一种有潜力的方法。通过机械功和功率的计算,可以量化不同日常身体活动的强度,为进一步研究日常活动能量代谢与健康的关系提供测量手段。

Objective The biomechanical models of three common daily physical activities were built to calculate mechanical work and power. The energy efficiencies of the activities were examined by using a room- size human indirect calorimeter. Methods The angles of legs, feet and trunk relative to the ground were measured by a multiple sensor system,and Langrangian equations were developed for the activities：sit to stand movement, trunk moving back and forth while sitting, and leg crossing while sitting. The energy expenditures of the activities were measured by human room-size indirect calorimeters. Results The mechanical powers calculated by the multiple sensor system were highly correlated with the metabolic rates measured by thecalorimeter （ correlation index： 0. 975 mechanical efficiencies were 27.1% ）. The average for sit to stan.d movement,21% for trunk moving back and forth, and 18% for leg crossing by using the joint power model. Conclusions Biomechanical model and joint power method are promising methods for the analysis of daily physical activity. By calculating the mechanical work and power, the intensity of physical activity can be quantified, whichprovides a method for the study of the relationship between energy expenditure of activities and health.