<prompt> Most common nerve used for nerve conduction study in H reflex -Median nerveUlnar nerveTibial nervePeroneal nerve  <response>: The H-reflex or Hoffmann;s reflex is a reflectory reaction of muscles after electrical stimulation of sensory fibers Ia afferents stemming from muscle spindles in their innervating nerves for example, those located behind the knee- Tibial nerve. The H-reflex test is performed using an electric stimulator, which gives usually a square-wave current of sho duration and small amplitude higher stimulations might involve alpha fibers, causing an F-wave, compromising the results, and an EMG set, to record the muscle response. REF : MAHESWARI 9TH ED 