Eight healthy young participants were included in the study. The purpose of this study was to investigate the effects of step width on the movement pattern of the head and trunk when walking on the treadmill using recurrence quantification analysis. Based on the results, the head and trunk moved in a deterministic pattern, and this pattern was stably repeated when walking on a wide base. Conversely, the head and trunk moved in an irregular pattern and showed high flexibility when walking on a narrow base.
