We found that variability in plantar pressure does not follow the same U-shaped curve relationship with speed, as do other lower limb step kinematic parameters. The strength of long-range correlations for each gait pattern consistently follows U-shaped curves, centred on the subjects preferred speed . RMA regression statistics support an increasing variability in plantar pressure with speed when assessed by m.s.e. in only 4 out of 16 subjects, but in 10 out of 16 subjects when assessed by CV (r2 > 0.75, p ≤ 0.05] (table 2) (figure 1). When speed was normalized by Froude number, we found support for a linear increase in plantar pressure variability when assessed by m.s.e. in 4 subjects, and in 11 out of 16 subjects when assessed by CV (r2 > 0.75, p ≤ 0.05) (table 3) (figure 3). Almost all the same subjects had strong statistical support between comparisons (tables 2 and 3); however, subjects exhibiting strong statistical support were not consistently the same by speed or Froude number. All four subjects who exemplify strong supporting statistics showed an increasing linear relationship between variability in plantar pressure and speed when assessed by m.s.e. (tables 2 and 3) (figures 1 and 3).