Objectives This study aimed to compare the estimation error of physical activity level (PAL) estimated using a tri-axial accelerometer between an independent walking group and an assisted walking group with walking aids. Methods Subjects were 6 older adults who could walk independently and 10 older adults requiring walking assistance during gait. Total energy expenditure (TEE) was measured using the doubly labelled water (DLW) method over 2 weeks and PAL was calculated as the measured TEE divided by the basal metabolic rate measured using indirect calorimetry (PALDLW). The participants wore a tri-axial accelerometer (Active style Pro HJA-750C) on the waist simultaneously as the DLW period, and the estimated PAL was derived from it (PALACC). Results The median PAL estimation error in the assisted walking group was −0.30 kcal/day (range: −0.77 to −0.01 kcal/day) and more underestimated than that in the independent walking group (p=0.02). The estimation error of PALACC was significantly correlated with PALDLW (r=−0.80, p<0.01). Conclusions Using the accelerometer, PAL was underestimated for older adults who used walking aids but not for those who walked independently under free-living conditions.

中文翻译：

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助行器对体弱老年人使用三轴加速度计估计体力活动的影响

目的 本研究旨在比较独立步行组和带助行器的辅助步行组之间使用三轴加速度计估计的体力活动水平 (PAL) 的估计误差。方法研究对象为6名能独立行走的老年人和10名需要步行辅助的老年人。在 2 周内使用双标水 (DLW) 方法测量总能量消耗 (TEE)，PAL 计算为测量的 TEE 除以使用间接量热法 (PALDLW) 测量的基础代谢率。参与者在 DLW 期间同时在腰部佩戴三轴加速度计（Active style Pro HJA-750C），并从中推导出估计的 PAL（PALACC）。结果 辅助步行组的 PAL 估计误差中位数为 -0.30 kcal/天（范围：-0.77 至 -0。01 kcal/天）并且比独立步行组更被低估（p = 0.02）。PALACC 的估计误差与 PALDLW 显着相关（r=-0.80，p<0.01）。结论 使用加速度计，使用助行器的老年人的 PAL 被低估了，但在自由生活条件下独立行走的老年人则没有。