The H-reflex study reveals differential finding according to each levels and various calf muscles in posterior compartment of lower leg. So, we studied how H-reflex responses undergo a change in accordance with each levels and various muscles of posterior calf.

Then, The results were as follows;

1) On the recording method by the surface electrode. H-wave represents a maximum amplitude of response on the level 5, as more distal site than midcalf location

2) Through the intramuscular recording method by monopolar needle electrode, the muscles of the posterior compartment of the lower leg are obtained each other differential, characteristic configuration, especially among the six muscles, the soleus shows a highest amplitude of H-response and modified H:M ratio(X=0.86).

3) The minimal latency of M and H responses was increment in proportion to the recording electrode is located more distally.

Therefore, this study indicates that a distal recording site is preferred to a midcalf location if the H-reflex per se is to be assessed.

Keywords :H-reflex, Intramuscular recording, Surface recording