Rapid return of H-reflex excitability to the baseline level
The return (i.e., decrease) of H-reflex size from the initial increase was significant over all participants and appeared to occur sooner among the Active tDCS group participants than the Sham group (Fig. Interestingly, once the H-reflex decreased back to the pre-tDCS level, with Active tDCS, the continuation of positive current over M1 did not continue to increase the presynaptic inhibition of the soleus H-reflex pathway to decrease reflex size beyond the pre-tDCS level. The absence of further reduction in the Active tDCS group’s H-reflex size from T4 to T22 may be explained by the negotiated equilibrium model of spinal cord plasticity (Wolpaw 