Figure 4.

Studies in healthy humans probing which afferents mediate the facilitation. A, Average from eight subjects of H-reflex amplitude with 18 ISIs between median nerve and conditioning ECR electrical stimulation at 3× MT, as in Figure 2, but while subjects had their wrist held in a flexed position. For one subject, data from seven ISIs (up to 5 ms) are not displayed as part of the average results due to stimulus artifact contamination. B, Average from six subjects of H-reflex amplitude with 18 ISIs between median nerve and conditioning passive wrist extension movement caused by mechanical perturbation. C, Average from five subjects of H-reflex amplitude with mechanical tap to FCR tendon as conditioning stimulation at 1× TT. Display conventions are as in Figure 2.