Data from: Speed dependency in α-motoneuron activity and locomotor modules in human locomotion: indirect evidence for phylogenetically conserved spinal circuits

Coordinated locomotor muscle activity is generated by the spinal central
pattern generators (CPGs). Vertebrate studies have demonstrated the
following two characteristics of the speed control mechanisms of the
spinal CPGs: (i) rostral segment activation is indispensable for achieving
high-speed locomotion; and (ii) specific combinations between spinal
interneuronal modules and motoneuron (MN) pools are sequentially activated
with increasing speed. Here, to investigate whether similar control
mechanisms exist in humans, we examined spinal neural activity during
varied-speed locomotion by mapping the distribution of MN activity in the
spinal cord and extracting locomotor modules, which generate basic MN
activation patterns. The MN activation patterns and the locomotor modules
were analysed from multi-muscle electromyographic recordings. The
reconstructed MN activity patterns were divided into the following three
patterns depending on the speed of locomotion: slow walking, fast walking
and running. During these three activation patterns, the proportion of the
activity in rostral segments to that in caudal segments increased as
locomotion speed increased. Additionally, the different MN activation
patterns were generated by distinct combinations of locomotor modules.
These results are consistent with the speed control mechanisms observed in
vertebrates, suggesting phylogenetically conserved spinal mechanisms of
neural control of locomotion.