Activity-Monitor Accuracy in Measuring Step Number and Cadence in Community-Dwelling Older Adults

TLDR

The study aimed to evaluate the accuracy of the activPAL monitor for step count and cadence in older adults. The study compared activPAL to two clinical pedometers (SW‑200 and NL‑2000) across treadmill and outdoor walking at multiple speeds in 21 older adults, using direct observation as the gold standard. activPAL recorded steps and cadence with <1% error in all treadmill and outdoor conditions, outperforming the SW‑200 (especially at slow speeds) and matching the NL‑2000 (<2% error except at the slowest speed), indicating it is a reliable and versatile tool for older adults.

Abstract

The primary purpose of this study was to investigate the accuracy of the acti vPAL physical activity monitor in measuring step number and cadence in older adults. Two pedometers (New-Lifestyles Digi-Walker SW-200 and New-Lifestyles NL-2000) used in clinical practice to count steps were simultaneously evaluated. Observation was the criterion measure. Twenty-one participants (65-87 yr old) recruited from community-based exercise classes walked on a treadmill at 5 speeds (0.67, 0.90, 1.12, 1.33, and 1.56 m/s) and outdoors at 3 self-selected speeds (slow, normal, and fast). The absolute percentage error of the ac ti v PAL was &lt;1% for all treadmill and outdoor conditions for measuring steps and cadence. With the exception of the slowest treadmill speed, the NL-2000 error was &lt;2%. The SW-200 was the least accurate device, particularly at slower walking speeds. The ac tivPAL monitor accurately recorded step number and cadence. Combined with its ability to identify primary postures, the activPAL might be a useful and versatile device for measuring activity in older adults.