Fig. 5

Comparison of gait analysis using IMU and video data. During stages B and C inertial measurement unit (IMU) data was collected using the GaitThaw device. Analysis of IMU data during the timed-up-and-go (TUG) test (segment 1) enabled comparison with observer analysis of video data during stage B (a-d) and stage C (e–h). Interventions analyzed were device worn, no cueing (NC); device worn, responsive (FOG-initiated) rhythmic vibration cueing (RC); device worn, continuous rhythmic vibration cueing (CC). a Step frequency from IMU data during stage B. b Step frequency from video data during stage B. c Step length from IMU data during stage B. d Step length from video data during stage B. e Step frequency from IMU data during stage C. f Step frequency from video data during stage C. g Step length from IMU data during stage C. h Step length from video data during stage C. Individual data points on graphs represent the mean response for an individual participant (a–d, n = 8; e–h, n = 11), with standard deviation indicated (a, b, e, f). A Kolmogorov–Smirnov test was used to test parametric distribution. Data in (a, b, d, f, g, h) were normally distributed and analyzed using paired t-tests. Data in (c, e) were not normally distributed and were analyzed using Wilcoxon matched-pairs signed rank tests. Significant differences indicated by asterisks: P < 0.05*, P < 0.01**