The antigravity soleus muscle (SOL) is crucial for compensation of stance perturbation. A corticospinal contribution to the compensatory response of the SOL is under debate. The present study assessed spinal, corticospinal and cortical excitability at the peaks of short (SLR), medium (MLR) and long latency responses (LLR) following posterior translation of the feet. Transcranial magnetic stimulation (TMS) and peripheral nerve stimulation were individually adjusted, so that the peaks of either motor evoked potential (MEP) or H-reflex coincided with peaks of SLR, MLR and LLR, respectively. The influence of specific - presumably direct - corticospinal pathways was investigated by H-reflex conditioning. When TMS was triggered so that the MEP arrived in the SOL at the same time as the peaks of SLR and MLR, EMG remained unaffected. Enhanced EMG was observed when the MEP coincided with the LLR peak (p < 0.001). Similarly, conditioning of the H-reflex by subthreshold TMS facilitated H-reflexes only at LLR (p < 0.001). The earliest facilitation following perturbation occurred after 86ms. The TMS induced H-reflex facilitation at LLR suggests that increased cortical excitability contributes to the augmentation of the LLR-peaks. This provides evidence that the LLR in the SOL muscle is at least partly transcortical involving direct corticospinal pathways. Additionally, these results demonstrate that approximately 86ms after perturbation postural compensatory responses are cortically mediated.