title: Coordination variability around the walk to run transition during human locomotion.
abstract: Increases in movement variability have previously been observed to be a hallmark property of coordination changes between coupled oscillators that occur as movement frequency is scaled. Prior research on the walk-run transition in human locomotion has also demonstrated increases in variability around the transition region, supporting predictions of nonequilibrium phase transitions (Diedrich & Warren, 1995). The current study examined the coordinative patterns of both intra- and inter-limb couplings around the walk-run transition using two different temporal manipulations of locomotor velocity as a control parameter in healthy young participants (N = 11). Coordination variability did not increase before the transition. The nature of the change in continuous relative phase variability between gait modes was coupling-specific, and varying the time spent at each velocity did not have an overall effect on gait transition dynamics. Lower extremity inter-limb coordination dynamics were more sensitive to changes in treadmill velocity than intra-limb coordination. The results demonstrate the complexity of segmental coordination change in human locomotion, and question the applicability of dynamical bimanual coordination models to human gait transitions.
authors.affiliation: Dept of Exercise Science, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Seay
authors.forename: Jeffery M
authors.initials: JM
authors.lastname: Haddad
authors.forename: Richard E A
authors.initials: RE
authors.lastname: van Emmerik
authors.forename: Joseph
authors.initials: J
authors.lastname: Hamill
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D011187:Posture / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D012016:Reference Values; D012420:Running / Q000502:physiology*; D016138:Walking / Q000502:physiology*