Waveform-Level Validation of Continuous Shank-to-Vertical Angle Measurement Using a Wearable Posture Sensor with Independent Video-Based Gait Event Detection.

Gait events for the wearable sensor were identified independently using synchronized tablet-based video recordings rather than inertial signals.

Across the full gait cycle, the trial-level waveform correlation was 0.935 ± 0.064 and the RMSE was 9.74 ± 3.71°.

For shank-to-vertical angle range, participant-level Bland-Altman analysis yielded a bias of -5.58° with 95% limits of agreement from -14.01° to 2.86°, and repeated-measures analysis produced similar estimates.