Effects of various walking speeds on probe reaction time during treadmill walking

The relative attention demanded by standing and walking at five velocities on a treadmill were examined by the measurement of probe reaction time (probe-RT). Subjects were 13 healthy men, who were from 21 to 42 years of age (M = 28.3 yr., SD = 7.4). The mean RT value was shortest at the velocity of 4 km/hr. and became longer at treadmill walking speeds above and below 4 km/hr. The mean preferred velocity of subjects obtained from 10-m free walking was 4.85 km/hr. (3.1 to 6.2 km/hr.), which is reasonably close to the optimal velocity of 4.0 km/hr. during treadmill walking. Walking at the optimum velocity calls for extremely low demands for attention, and walking at velocities higher or lower than this requires more attention.