RELlABlLlTY AND VALIDATION OF AN INERTIAL SENSOR USED TO MEASURE ORIENTATION ANGLE

Abstract

This study examined the reliability and validity of an inertial measurement unit (IMU) for measuring orientation angle. An IMU was mounted onto a goniometer and moved through 0-90' with data collected at 10' increments. The process was repeated 10 times for all 3 axes. Reliability was measured via a typical error (TE) analysis from the 10 repeated trials. Validity was determined via a Pearson correlation and an ordinary least products (OLP) regression. The lMU was very reliable for all 3 axes (TE: x=0.03", y=0.03", z=0.02").T he Pearson correlation between the IMU and goniometer was large and significant for all 3 axes (r = 1.00,95%CI = 1 .O-1.0). The OLP regression showed no proportional bias for the 3 axes and only small fixed blas for the x and z axes. Overall the IMU tested was very reliably and accurate at measuring orientation angle.