Neurophysiological mapping post implant. (A) An example of reconstructed spinal cord model and estimated paddle placement (Subject A68). (B) List of electrode contact combinations tested during spatiotemporal neurophysiological mapping post implant in supine position (frequency 2 Hz, pulse width 450 or 1000 µs, intensity voltage or milliampere ramps up from zero until all muscles show induced activation). (C) Examples of corresponding overlaid motor evoked potentials (overlaid temporal activities with amplitudes low to high correspond to evoked response averages to different stimulation intensities) and muscle recruitment curves (peak-to-peak amplitude µV) for each electrode combination tested across 14 muscles including left and right SOL, MG, TA, VL, RF, MHs and GL. (D) Each panel shows overlaid responses to stimulation pulses at the same stimulation intensity (usually between 3 and 5 pulses are delivered for each stimulation intensity) and the example of first visible motor evoked potential during stimulation ramp-up. (E) Identifying the activation threshold, i.e. the amount of intensity that led to first visible motor evoked potential and the estimation of the slope of the recruitment curve from fitted sigmoid function.