Effect of ankle dorsiflexion range of motion on rearfoot motion during walking.

The purpose of this study was to investigate whether the amount of ankle passive dorsiflexion range of motion influences the pattern of frontal plane rearfoot motion during walking. Three-dimensional motion of the rearfoot was measured in two groups of subjects, those with ankle passive dorsiflexion range of motion less than or equal to 10 degrees, and those with ankle passive dorsiflexion range of motion greater than 15 degrees, while they walked along a 6.1-m walkway. The results indicated that the only statistically significant differences between the two groups were in the time to reinversion of the rearfoot and the time to heel-off. Slight-to-moderate limitation of ankle passive dorsiflexion range of motion significantly alters the timing, but not the magnitude, of frontal plane rearfoot motion during walking.