Validity of gait parameters of healthy young adults using a motion-sensor-based gait analysis system (ORPHE ANALYTICS) during walking and running

BackgroundMotion sensors are widely used for gait analysis. ORPHE ANALYTICS is a motion-sensor-based gait analysis system. The validity of commercial gait analysis systems is of great interest to clinicians because calculating position/angle-level gait parameters using motion sensor data potentially produces an error in the integration process; moreover, the validity of ORPHE ANALYTICS has not yet been examined. Research questionHow valid are the position/angle-level gait parameters calculated using ORPHE ANALYTICS relative to those calculated using conventional optical motion capture? MethodsNine young adults performed gait tasks on a treadmill at speeds of 2-12 km/h. The motion sensors were mounted on the shoe midsole (plantar-embedded) and shoe instep (instep-mounted). The three-dimensional marker position data of the foot as well as the acceleration and angular velocity data of the motion sensors were collected. The position/angle-level gait parameters were calculated from motion sensor data obtained using ORPHE ANALYTICS and optical motion capture data. Intraclass correlation coefficients [ICC(2,1)] were calculated for relative validities, and Bland-Altman plots were plotted. ResultsEight items, namely, stride duration, stride length, stride frequency, stride speed (plantar-embedded), vertical height (plantar-embedded), stance phase duration, swing phase duration, and sagittal angleIC, exhibited excellent relative validities [ICC(2,1) > 0.9]. In contrast, the sagittal angleTO demonstrated good relative validity [ICC(2,1) = 0.892-0.833], while the frontal angleIC exhibited moderate relative validity [ICC(2,1) = 0.566-0.627]. SignificanceORPHE ANALYTICS, a motion-sensor-based gait analysis system, was found to exhibit excellent relative validity for most gait parameters. This finding suggests its feasibility for gait analysis outside the laboratory setting. HighlightsO_LIGait-parameter validities were examined for treadmill-based gait tasks at 2-12 km/h. C_LIO_LIMost gait parameters showed excellent relative validity with optical motion capture. C_LIO_LIShoe midsole-embedded sensors had higher validities than instep-mounted sensors. C_LIO_LIORPHE ANALYTICS is potentially useful in clinical measurements. C_LI