Neural control of walking as revealed by the velocity field diagram.

The walking patterns of 13 healthy adult subjects were studied with a low technology method of gait analysis, the velocity field diagram (VFD). The intent was to explore neural control of gait by an understanding of the pattern of interaction of the parameters during walking. Subjects were asked to walk along a level walkway at five speeds, from very slow to very fast. Strides were counted and the time taken to walk the distance was recorded by means of a stop-watch. The numerical values of velocity, stride length and stride frequency were plotted against speed numbers derived by serially numbering the five speeds of walking. There was repeat recording of gait. The interacting pattern of gait parameters in the VFD was similar in all subjects and they easily formed into equations. Related gait regressions were derivable from VFD equations. Most parameters of the VFD were highly reproducible. Equations, definitions of various speeds, zoning of the VFD and other VFD descriptors were shown as indicators of neural control and clinical tools to watch during gait assessment and training. The role of the deep cerebellar nuclear complex in the determination of walking speed was highlighted.