Fig. 2

Post-stimulation depression of evoked responses confirms elicitation of posterior root-muscle (PRM) reflexes. a Electrode position for elicitation of muscle responses via transcutaneous SCS. b Afferent stimulation is confirmed by the depression and partial recovery of the PRM reflex using a paired-pulse paradigm (Minassian et al. 2007b; Hofstoetter et al. 2018; Kagamihara et al. 1998; Hofstoetter et al. 2020). Exemplary electromyographic responses of the leg muscles when the time between stimuli is set to 30, 50, and 100 ms. Responses to the second stimulus are completely eliminated at interstimulus intervals of 30 ms and partially recover at 100 ms (Hofstoetter et al. 2019). Modified with permission from (Hofstoetter et al. 2021)