Voluntary drive amplifies effects of paired-pulse tms and arm posture on biceps corticomotor excitability

Non-invasive brain stimulation techniques are typically applied at rest, but may be more effective or representative of neural changes when applied during a range of voluntary effort. We investigated the effect of voluntary drive on intracortical facilitation (ICF), short-interval intracortical inhibition (SICI) and static arm posture (AP) in the non-impaired biceps. We found that high voluntary effort (≥ 50% MVC) increased ICF, SICI, and static elbow angle mediated changes in biceps corticomotor excitability. Thus, changes in corticomotor excitability may be more detectable at high voluntary effort.