Intra-axonal recording of PADs during fictive locomotion. Traces, Top tobottom, Eight PADs (tilted 90°) recorded in a group I fiber from SmAB and evoked by PBSt stimulation (3 p, 5 T, 300 Hz); continuous intra-axonal recording from the afferent; and locomotor ENG activities of FDHL, Pl, and TA/EDL.