Head deflections during walking and running

Deflections of the head during level, straight, steady-state walking and running are considered. The literature is reviewed regarding the relationships between the forward speed, the step frequency, and the vertical, lateral, and fore-aft components of head motion for healthy adults. Typically: (i) the vertical amplitude of the head decreases as the speed of locomotion increases; (ii) the lateral amplitude increases as the speed of walking increases, reaches a maximum value in the jogging range (relatively slow running), and then decreases as the running speed increases; and (iii) the fore-aft amplitude (relative to the average forward motion) is small and does not vary significantly with speed. Based on the results presented in the literature, formulas are proposed for these three dynamic components of head motion.