In this work the changes of velocity conduction on segments S1-root are described at the acute lumbar discs hernia with sciatic pain. The change is traced in process of increase hernias size revealed NMR study in the surveyed group. This change velocity was connected with alpha-motoneurons suppression and activation. Except early stage (1a-1b phases), every change conduction velocity was followed the growth discs hernia size on 2 mm 6,86+1,83 mm, 7,07+2,0 mm, 9,14+5,69 mm, 11,3+6,06 mm. For an explanation of change velocity of conduction four original concepts are offered.