H-reflex excitability is inhibited in soleus, but not gastrocnemius, at the short-latency response of a horizontal jump-landing task

•H-reflex excitability is modulated in soleus, but not medial gastrocnemius during landings.•Changes in H-reflex excitability more likely represented Ia-afferent activity.•A new, reliable method to assess H-reflex excitability during landings. Impaired spinal-level neuromuscular control is suggested to contribute to instability and injury during dynamic landing tasks. Despite this suggestion, spinal-level neuromuscular control is yet to be examined during a horizontal jump-landing task. The aim of the current study was to assess changes in H-reflexes and its reliability at the short-latency response of landings from short and long distances. Eight healthy individuals (five male, three female; age, 22±1.2yrs; height, 178±8.1cm; weight, 72±15.7kg) participated in the study. H-reflexes were evoked at the SLR in the soleus and medial gastrocnemius muscles, during two landing conditions: 25% and 50% of maximal broad jump distance. H-reflexes were expressed relative to the background electromyography (EMG) and maximal M-wave responses (M-max). Soleus H-reflexes were inhibited when landing from shorter distance (25%, 13.9±7.6%; 50%, 8.3±6.5%; p