Fig 1.
Examples of stride-to-stride fluctuations.
Representative examples of stride-time, stride-length and stride-speed time series for two non-isochronous metronome conditions with anti-persistence (α0.2, left panel) and persistence (α0.9, right panel) in interbeat intervals. The correlation between stride-times and stride-length time series was positive, and much stronger for the persistent (r = 0.61, right panel) than for the anti-persistent (r = 0.36, left panel) metronome condition.
Fig 2.
Scaling exponents for original and surrogate time series.
DFA scaling exponents α for stride speeds (left panel), stride times (center panel) and stride lengths (right panel) for uncued treadmill walking (UC) and isochronous (ISO) and non-isochronous (α0.2, α0.5, α0.6, α0.9) metronome conditions. DFA scaling exponents α are given for original time series (gray circles) as well as for phase-randomized and cross-correlated phase-randomized surrogates (black diamonds and white squares, respectively).
Fig 3.
Maximal displacement and coupling strength.
Results of maximal displacement along the treadmill (left panel) and the coupling strength between stride times and stride lengths (right panel) for uncued treadmill walking (UC) and isochronous (ISO) and non-isochronous (α0.2, α0.5, α0.6, α0.9) metronome conditions.