Accuracy of two algorithms for gait events detection in free-living settings

The aim of this study was to evaluate the accuracy of two algorithms for the detection of gait events and temporal parameters during free-living walking. The algorithms, one based on two shankworn inertial sensors, and the other based on one waist-worn sensor, were applied to gait data of ten healthy subjects walking both indoor and outdoor, and completing protocols that entailed both straight supervised and free unscripted walking. The values obtained from the inertial sensors were compared to pressure insoles data. The shank-based method showed very accurate initial contact, stride time and step time estimation. Accuracy of final contact timings and stance time was more critical. The waist method performed worse than the shank method, but the temporal parameter estimation was still satisfactory. Both methods showed negligible differences in their accuracy when the different experimental conditions were compared, which is encouraging for their application in the analysis of free-living gait.