Lower-limb Coordination Varies with Steps During Gait Initiation

Gait initiation is a transient phase from standing to a stable walking. Compared to a stable gait, it requires more efforts to prevent falls. Therefore, gait initiation deserves more attention for gait analysis and pathology diagnosis. However, traditional gait detection is focused on stable gait, and the movement of a single joint cannot reflect the motor coordination of the whole lower limb. In this paper, fourteen healthy people were recruited and the lower-limb joint angles in swing phases of the initiate five steps were collected. The lower inter-joint coordination was calculated using the Continuous Relative Phase (CRP) method based on Hilbert transform. The results showed that the Mean Absolute Relative Phase (MARP) does not discriminate between gait initiation and stable gait phases, while the Deviation Phase (DP) of the joint couplings of the lower extremities decreases and stabilizes with the increasing number of steps. Variability in CRP has the potential to be a marker of stable gait.