Gait transitions are not dependent on changes in intralimb coordination variability

The HKB model (H. Haken, J. A. S. Kelso, & H. Bunz, 1985) of coordination has been predominantly applied to upper extremity stationary movements. It predicts increased variability of relative phase before a transition and a decrease after a transition. The authors of the present study extended the intralimb lower extremity locomotive research of F. J. Diedrich and W. H. Warren (1995) by conducting continuous treadmill walk-to-run and run-to-walk trials with 10 participants. Standard deviation of knee-ankle and hip-ankle relative phase did not increase before walk-to-run and run-to-walk transitions, and there was no decrease in knee-ankle relative phase variability after either transition. The results of this study did not provide strong support for application of the variability predictions of the HKB model of coordination to lower extremity intralimb coordination during gait transitions.