Fig. 5. Step frequency (f) changes during curve walking, but not in a unilateral way. Average step frequencies of each leg during straight walking (white bars, first 7.5 s interval) and curve walking (grey hatched bars, third 7.5 s interval). Values are means ± S.D. of 33 trials from eight animals. Outer front, middle and hind legs (O1 to O3, respectively) significantly increase their step frequency during curve walking. So does the inner front leg (I1). Inner middle and hind legs (I2 and I3) show no statistically significant change. Wilcoxon test for matched pairs with H₀: f_straight=f_curve; N=33; ^***P0.001; ^**P0.01. All contralateral leg pairs step at the same frequency during straight walking (P>0.3), but at different frequencies during curve walking (P0.002)