Fig. 2. — Reflex contraction of extensor muscle of knee. 



Contraction of the muscle is indicated by rise of the myograph line, relaxation by fall. Upper signal line 

 shows period of stimulation of ipsilateral peroneal nerve; lower signal shows stimulation of contra- 

 lateral popliteal nerve. The observation opens with stimulation of the former with weak faradisation ; 

 the tonus of the muscle is reflexly inhibited and the muscle relaxes. The contralateral nerve is then 

 stimulated, the stimulation of the ipsilateral (inhibitory) nerve still continuing ; the muscle contracts 

 reflexly and it might appear as if the inhibitory reflex was having no eff"ect ; the stimulation of the 

 inhibitory nerve (ipsilateral) is then discontinued while that of the excitatory (contralateral) still 

 continues. The height of the reflex contraction then assumes a higher level. The degree of reflex 

 contraction under the opposed influences of the two nerves is thus seen to represent an algebraic 

 summation of their plus and minus effects. Time above in seconds. 



