Marsh Anthony P, Vance Rachel M, Frederick Tera L, Hesselmann Sarah A, Rejeski W Jack
Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC 27109-7868, USA.
Med Sci Sports Exerc. 2007 Jun;39(6):1020-6. doi: 10.1249/mss.0b013e3180423ac3.
The purpose of this study was to evaluate the validity of three objective measures of physical activity (Accusplit Eagle 120 mechanical pedometer (AE120), NL-2000 electronic pedometer, and IDEEA pattern-recognition device) that varied in their levels of sophistication, among older adults at risk for mobility disability. In addition, we examined the potential influences of gait speed and body mass index (BMI) on step count accuracy.
Step counts recorded on the three devices were compared against manual step counts made by two investigators as each participant walked 131 m around an indoor track at their preferred walking speed (N=29; 75.8+/-4.2 yr). Gait speed was determined by dividing total distance walked by time to completion. BMI was calculated from height and body mass measurements.
All three devices significantly underestimated steps taken (AE120=22.8+/-53.9 steps; NL-2000=4.0+/-5.8 steps; IDEEA=5.6+/-7.8 steps), but there was no significant difference between devices (P=0.084). Steps counted by the AE120, NL-2000, and IDEEA were significantly correlated with manual step counts (r=0.508, 0.980, and 0.965, respectively; P<or=0.005). However, the AE120 was not clinically acceptable, sharing only 26% common variance with actual steps taken. The accuracy of the three devices was not influenced systematically by either gait speed or BMI.
Our data show that the AE120 is a poor choice for measuring physical activity in older adults at risk for mobility disability. Both the NL-2000 and IDEEA devices have acceptable measurement qualities; however, the NL-2000 is the more practical of the two for use in either research or clinical practice.
本研究旨在评估三种不同复杂程度的身体活动客观测量方法（Accusplit Eagle 120机械计步器（AE120）、NL - 2000电子计步器和IDEEA模式识别设备）在有行动能力残疾风险的老年人中的有效性。此外，我们还研究了步速和体重指数（BMI）对步数计数准确性的潜在影响。
在每位参与者以其偏好的步行速度在室内跑道上行走131米时（N = 29；年龄75.8±4.2岁），将三种设备记录的步数与两名研究人员手动计数的步数进行比较。步速通过总步行距离除以完成时间来确定。BMI根据身高和体重测量值计算得出。
所有三种设备均显著低估了所走步数（AE120 = 22.8±53.9步；NL - 2000 = 4.0±5.8步；IDEEA = 5.6±7.8步），但各设备之间无显著差异（P = 0.084）。AE120、NL - 2000和IDEEA计数的步数与手动计数步数显著相关（分别为r = 0.508、0.980和0.965；P≤0.005）。然而，AE120在临床上不可接受，与实际所走步数的共同方差仅为26%。三种设备的准确性均未受到步速或BMI的系统性影响。
我们的数据表明，对于有行动能力残疾风险的老年人，AE120是测量身体活动的不佳选择。NL - 2000和IDEEA设备均具有可接受的测量质量；然而，在研究或临床实践中，NL - 2000在这两种设备中更为实用。
