Horvath Sylvia, Taylor David G, Marsh Jonathan P, Kriellaars Dean J
Human Performance Laboratory, School of Medical Rehabilitation, University of Manitoba, Winnipeg, Canada.
Appl Physiol Nutr Metab. 2007 Jun;32(3):409-15. doi: 10.1139/H07-001.
Manufacturers of pedometers recommend wearing a pedometer on the midline of the right thigh and this recommendation is used in research. However, there is conflicting evidence regarding the effect of pedometer position on accuracy. The purpose of this study was to systematically evaluate the effect of pedometer position on accuracy for 3 modes of gait. The Yamax SW200 pedometer was evaluated in 20 subjects in 5 different positions simultaneously: left mid-axillary, left mid-thigh, umbilical, right mid-thigh, and right mid-axillary. Each subject was asked to walk on a treadmill (54, 80, and 107 m.min(-1)), to walk overground (slow, preferred, and fast speeds), and to ascend and descend stairs. Pedometer steps were recorded and compared with actual steps observed. Using the same protocol, instantaneous triaxial accelerometry was used to explain position-dependent differences in accuracy. At slow speeds, the left mid-axillary position demonstrated the lowest net mean (+/-SD) error across all modes of gait (7.7% (+/-11.6%) overground;-0.6% (+/-2.2%) stairs). The right mid-thigh position had significantly (p<0.01) higher error for treadmill (18.1% (+/-17.3%)), overground (12.9% (+/-15.2%)), and stairs (2.9% (+/-3.9%)). Pedometer position dependent error was demonstrated, with the left mid-axillary position superior to the recommended position of right mid-thigh. The greater accuracy on the left side was wholly explained by gait asymmetry evident in step-induced accelerations recorded at right and left pedometer positions. A model of absolute error based on the ratio of steps at different gait speeds was generated to demonstrate the importance of this finding in pedometer-based lifestyle intervention studies.
计步器制造商建议将计步器佩戴在右大腿的中线上，研究中也采用了这一建议。然而，关于计步器位置对准确性的影响，存在相互矛盾的证据。本研究的目的是系统评估计步器位置对三种步态模式准确性的影响。对Yamax SW200计步器在20名受试者身上同时进行了5个不同位置的评估：左腋中线、左大腿中部、脐部、右大腿中部和右腋中线。要求每位受试者在跑步机上行走（速度分别为54、80和107米·分钟⁻¹）、在地面行走（慢、正常和快三种速度）以及上下楼梯。记录计步器步数并与实际观察到的步数进行比较。采用相同方案，使用瞬时三轴加速度计来解释准确性方面的位置依赖性差异。在慢速度时，左腋中线位置在所有步态模式下的净平均（±标准差）误差最低（在地面行走时为7.7%（±11.6%）；上下楼梯时为-0.6%（±2.2%））。右大腿中部位置在跑步机行走（18.1%（±17.3%））、地面行走（12.9%（±15.2%））和上下楼梯（2.9%（±3.9%））时的误差显著更高（p<0.01）。计步器位置依赖性误差得到证实，左腋中线位置优于推荐的右大腿中部位置。左侧更高的准确性完全可以通过左右计步器位置记录的步幅诱导加速度中明显的步态不对称来解释。生成了一个基于不同步态速度下步数比例的绝对误差模型，以证明这一发现计步器为基础的生活方式干预研究中的重要性。
