青年人站立能量消耗水平及分型研究

Research on the Level and Type of Energy Consumption of Young People

目的:测量青年人稳定站立时的能量消耗水平,探究站立能量消耗分型的原因,为久坐少动行为的干预提供实证依据。方法:本研究分为两部分:研究1中的42名受试者(男性19人、女性23人)依次完成静坐-站立-静坐任务,每个阶段10 min,中间间隔2 min,采用MAX-Ⅱ气体代谢分析系统、AMTI三维测力台和NORAXON表面肌电采集系统分别进行能量消耗、身体无意识晃动和下肢主要肌肉肌电的测量,通过差异检验和logistic回归探讨站立能耗分型的原因。研究2模拟放松时站立情况,18名青年人(男女各半)完成站立、站立踱步、站立原地单脚移步和站立原地双脚移步任务,分析MAX-Ⅱ收集的代谢数据确定不同形式站立的能耗水平。结果:(1)研究1中,42名受试者中有30名受试者为站立能耗节约型,男女受试者在能耗分型上并无显著性差异(χ^2=0.487,P=0.472),足底压力中心点移动距离、内侧腓肠肌积分肌电增长值和股直肌积分肌电增长值的比值比(OR)分别为13.02、1.89和15.75,P值分别为0.027、0.023和0.013,两类受试者在心率、呼吸频率和呼吸商上的差异并无统计学意义。(2)研究2中,站立、站立踱步、站立单脚移步和站立双脚移步的代谢当量(METs)分别为1.23、1.45、1.59和1.67。结论:相对于静坐,稳定站立时能量消耗的增幅有限;青年人中大部分个体在能耗分型上均属于节约型;分型与维持人体站立姿态相关的下肢肌肉的响应以及身体无意识的晃动有关。

Objectives To assess the energy consumption level and type of steady-state standing,so as to provide empirical evidences for the intervention of sedentary behaviors. Methods This study was divided into two parts. In part 1,42 subjects(19 males and 23 females) completeda 30-minute sit-stand-sit task in turn with an interval of 2 minutes between each 10-minute stage. The MAX-Ⅱ gas metabolism analysis system,AMTI three-dimensional force platform,and NORAXON surface electromyography collection system were used to measure the energy consumption,body unconscious sway and main muscle myoelectricity of lower limbs respectively. The type of the energy consumption was analyzed via the differentiation test and logistic regression. In part 2,18 young people(half males and half females) conducted standing,standing with pacing,standing with one-leg displacement and twoleg displacement. The MAX-Ⅱ was used to collect metabolic data to determine energy consumption levels of different forms of standing. Results In part 1,30 out of 42 subjects wereenergy-savers,and there was no significant difference in the type of energy consumption between two genders(χ^2=1.167,P=0.280). The odd ratio of the distance of center of plantar pressure,the integrate electromyography improvement of the medial gastrocnemius and rectus femoriswere 13.02, 1.89 and 15.75 respectively,and P values were 0.027, 0.023 and 0.013 accordingly. No significant differences were observed in the heart rate,breathing rate and respiratory quotient between males and females. In part 2,the metabolic equivalent of standing,standing with pacing,standing with one-leg displacement and two-leg displacement was 1.23,1.45,1.59 and 1.67 respectively. Conclusion Compared with sitting,the increase in energy consumption of steady-state standing waslimited.In terms of the energy consumption, most young people are energy-savers during standing. The type of energy consumption when standing was related to the response of lower limb muscles and the spontaneous weight-shifting.