Characteristic frequency of muscle response to electrical stimulation in normal and hypokalemic rats

Abstract

This paper examines frequency characteristics of muscle, which show differences between slow and fast twitch fiber type muscle in normal and hypokalemic rats. The characteristics of muscle stimulating frequencies and EMG amplitude was studied by using control theory. The EMG was recorded from soleus (slow twitch fiber type) and extensor digitorum longus (fast twitch fiber type) in vivo. It was found that muscle showed different frequency response, and that under hypokalemia each muscle showed poor response. Furthermore, in response to electric stimulation to achieve an equivalent level of response, it was found that muscle needed higher electric intensity than nerve-muscle and muscle showed remarkable decay under hypokalemia. These results suggest that the main disease origin under hypokalemia can be ascribed to muscle condition, and that it is most efficient to stimulate nerves in order to control muscle.