Distinct sets of locomotor modules control the speed and modes of human locomotion.
Although recent vertebrate studies have revealed that different spinal networks are recruited in locomotor mode- and speed-dependent manners, it is unknown whether humans share similar neural mechanisms. Here, we tested whether speed- and mode-dependence in the recruitment of human locomotor networks exists or not by statistically extracting locomotor networks. From electromyographic activity during walking and running over a wide speed range, locomotor modules generating basic patterns of muscle activities were extracted using non-negative matrix factorization. The results showed that the number of modules changed depending on the modes and speeds. Different combinations of modules were extracted during walking and running, and at different speeds even during the same locomotor mode. These results strongly suggest that, in humans, different spinal locomotor networks are recruited while walking and running, and even in the same locomotor mode different networks are probably recruited at different speeds.
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.|Research Fellow of the Japan Society for the Promotion of Science, Tokyo, Japan.
Hikaru
H
Yokoyama
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.
Tetsuya
T
Ogawa
Department of Rehabilitation for the Movement Functions, Research Institute of National Rehabilitation Center for the Disabled, 4-1 Namiki, Tokorozawa, Saitama 359-8555, Japan.
Noritaka
N
Kawashima
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.
Masahiro
M
Shinya
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.
Kimitaka
K
Nakazawa
D000328:Adult; D004576:Electromyography / Q000379:methods; D005684:Gait / Q000502:physiology; D006801:Humans; D008124:Locomotion / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D012420:Running / Q000502:physiology; D016138:Walking / Q000502:physiology; D055815:Young Adult