Using a robotic arm to assess the variability of motion sensors.

For the assessment of physical activity, motion sensors have become increasingly important. To assure a high accuracy of the generated sensor data, the measurement error of these devices needs to be determined. Sensor variability has been assessed with various types of mechanical shakers. We conducted a small feasibility study to explore if a programmable robotic arm can be a suitable tool for the assessment of variability between different accelerometers (inter-device variability). We compared the output of the accelerometers GT1M and GT3X (both ActiGraph) and RT3 (Stayhealthy) for two different movement sequences.