Fig. 3: Results for the control of interlimb coordination for one representative subject (Subject G).
From: Interlimb coordination is not strictly controlled during walking
a Phase sensitivity functions Zi(ϕi) (i ∈ (L, R)) for acceleration (Acc), deceleration (Dec), and mixed (Mix) conditions. b Control of interlimb coordination, represented by f(ΔLR). The vertical dotted lines indicate 3 standard deviations from the mean of the observed ΔLR. In the region outside the vertical dotted line, the estimated function f(ΔLR) is displayed in pale color. The function f(ΔLR) is shifted in order to place the mean of the observed values of ΔLR at π to improve visualization. The histogram displays the noise intensity, σLR. (An expanded histogram, with values 30 times larger than the actual values, is also given.) The mean and standard deviation of the derived noise intensity for all results are 0.0106π and 0.0021π, respectively. These values are too small to cause deviation of ΔLR from the flat region of f(ΔLR). c A schematic diagram for the interpretation of f(ΔLR). The flat region near ΔLR = π at B (neutral stability) and the steep negative slope in the regions away from π reflect the fact that the relative phase between the legs is not actively controlled until the deviation from π exceeds a threshold (ΔA − π at A and ΔC − π at C), where motion of the legs deviates significantly from the antiphase relationship.
