Gait Event Detection During Running Using a Bending Angle Sensor Attached to Loose-Fitting Clothing.

The purpose of this study was to verify the accuracy of cycle time (tg) and contact time (tc) during running using a bending angle sensor attached to loose-fitting clothing in comparison with 3D motion capture data. For the measurements, 20 healthy adult males wore loose-fitting pants with a bending angle sensor attached to the right knee. They ran on a treadmill at 8, 10, and 12 km/h for 90 s. A 3D motion capture device and the bending angle sensor simultaneously measured the right knee joint motion. Knee extension peaks for acquiring foot-strike and toe-off were detected from knee joint angular acceleration to acquire tg and tc from the sensor data. The absolute mean error (MAE), mean bias error (MBE), and root mean square error (RMSE) for tc and tg were obtained. The RMSE for tc was 21.4 ms at 8 km/h and less than 20 ms at 10 and 12 km/h, while the MAE, MBE, and RMSE were all within 10 ms for tg. These results indicate that the bending angle sensor attached to loose-fitting clothing enables tg and tc detection.