Effects of changing protocol, grade, and direction on the preferred gait transition speed during human locomotion.

Although the preferred transition speed (PTS) reported by various researchers is relatively consistent, the amount of observed hysteresis (difference between the walk-run and the run-walk transition speed) varies considerably. Variations in reported hysteresis appear to be related to the protocol used to determine the transition speeds. This investigation compared the PTS, and the amount of hysteresis observed between the incremental and continuous protocols at various inclination conditions. The PTS was significantly greater in the continuous than the incremental protocol within both the 10% and 15% inclination conditions. The amount of hysteresis, however, did not vary significantly between protocols nor between inclination conditions. In the incremental protocol, the amount of hysteresis appears to be related to the size of the speed increment used. In the continuous protocol, the amount of hysteresis could be related to the rate of treadmill acceleration.