Evaluation of different kind of pedometers measuring walking steps at different speeds

Evaluation of different kind of pedometers measuring walking steps at different speeds Anna Akerberg and Maria Linden The School of Innovation, Design & Engineering, Malardalen University, Vasteras, Sweden INTRODUCTION: A common method to measure physical activity is with a pedometer, which counts number of steps taken. The pedometer is seen as an acceptable tool by both researchers and the public, although, research shows that traditional pedometers are capable of both over- and underestimate steps taken. It is now common that pedometers are integrated in other devices, such as cell phones, which enables measurements by a product already worn by a huge part of the population. To assess the potential of pedometers in cell phones, and to contribute to increase physical activity and a better health, they need to be evaluated and compared with traditional pedometers. PURPOSE: to evaluate the measurement accuracy of a pedometer cell phone application compared to traditional pedometers, measuring walking steps at different speeds. METHODS: Walking steps was measured by two pedometers and one pedometer cell phone application, on one individual (Female, 38 y, BMI: 30) walking on a motorized treadmill (Attract), at 7% slope. Equipment: Yamax LS2000 (Y) (Yamax, Japan)on the right hip, Omron Walking Style X (O) (Omron Health Care, Japan) in the left chest pocket and an iPhone 4S (Apple Inc., California, USA. SW: iOS6.0.1), in the right chest pocket, using the Pedometer Ultimate GPS+ (A) (Arawella Corp., V: 3.3.2) (walking sensitivity medium level). All pedometers were carried according to the manufacturers’ recommendations, and in the same position of all measurements. 200 walking steps were performed ten times at five speeds; 0.6, 1.2, 2.5, 3.0, 4.0 mph and the steps were also counted manually. The right target speed was held from the beginning of the measurement, and the pace of the steps was held with help of a metronome (Korg Micrometro MCM-1). Mean values and standard deviation was calculated. RESULTS: The steps were severely underestimated for all three pedometers at 0.6 mph (A=3.5±1.4, O=0.0±0.0 and Y=5.8±1.8) and 1.2 mph (A=5.2±3.1, O=137.4±39.5 and Y=21.2±17.7). The measurements could be regarded as good for both A (197.0± 7.7) and O (198.6±1.0) at 2.5 mph, where Y still underestimates (112.9±58.5). The same result at 3.0 mph (A=203.8±5.4, O= 199.2±1.9 and Y= 154.4±24.6). All pedometers measured about the same at 4.0 mph (A=170.3±15.7, O=185.7±6.4 and Y=171.7±20.2). CONCLUSION: The study shows that the evaluated pedometers cannot perform acceptable measurements in all five walking speeds, ranging from very slow to fast normal walking speed. However, both A and O, produce accurate measurements at speeds considered to be medium-fast. This limited study shows that A and O performs more accurate measurements compared to Y. Supported by: NovaMedTech