Intermonitor Variability of RT3 Accelerometer during Different Activities

Abstract

Purpose of this study was to analyze reliability and variability of the RT3 accelerometers. The RT3 was administrated to two repeated trials of six activities; rest, two steps, walking, and two running. One person performed all trials (male: age 28 yr, 169cm, 63kg). Each activity lasted 12min. Data were analyzed for activity, monitor, and trial effects. The replacement of monitors also analyzed for left and right side differences and association between heart rate and accelerometer counts was analyzed. A three-way interaction was found for vector magnitude (F35.0 = 190732.08 p<0.029) and X (F35.0 = 267589.97, p<0.001) and Y (F35.0 = 182169.56, p<0.001) and Z axes (F35.0 = 815995.11, p<0.001). A two way interaction was found for VM (p<0.002), X, Y, and Z axes (p<0.001). Placement differences between right and left monitors were found for vector magnitude, X and Z axes. At both trials 1 and 2 there was no significant heart rate differences. The Y axis of the RT3 accelerometer was the most reliable in this study. RT3 accelerometer is reliable for physical activity level.