. On Innervation of Antagonistic Muscles. Ninth Spinal Induction . been obtained with mechanical,as well as electrical stimulation, of the nerve. It has also been obtained bystimulation of the central end of the whole vasto-crureus nerve after totalseverance of that nerve; the extension then obtained is due to extensors athip and ankle, and guarantees that, in the rebound reflex, these latterextensors, as well as the extensors of the knee, are thrown into contraction. The difficulty expressed in the concluding sentence above, of applyingsuccessive induction and rebound contra
. On Innervation of Antagonistic Muscles. Ninth Spinal Induction . been obtained with mechanical,as well as electrical stimulation, of the nerve. It has also been obtained bystimulation of the central end of the whole vasto-crureus nerve after totalseverance of that nerve; the extension then obtained is due to extensors athip and ankle, and guarantees that, in the rebound reflex, these latterextensors, as well as the extensors of the knee, are thrown into contraction. The difficulty expressed in the concluding sentence above, of applyingsuccessive induction and rebound contraction to explain natural alternating reflexes, because of the lengthy and intense stimuli required to obtain themexperimentally, is therefore greatly lessened. An instance of distinctrebound, induced by quite brief inhibition, is furnished in a figureillustrating the notef on innervation of antagonistic muscles next preceding ^ . Fia. 9.~-Myograph record of reflex contraction of extensor of knee interrupted by a reflexinhibition (relaxation). The reflex contraction was induced by stimulation (unipolarfaradisation) of the skin of the opposite foot: this stimulation was applied during thetime marked by the lower signal; its movements of commencement and ending arenjarked by abscissae on the myogram. Towards the height of the reflex contractiona brief stimulation (unipolar faradisation) was applied to. the skin of the foothomonymous with the knee extensor yielding the myogram : the duration of thisinhibiting stimulus is marked by the upper signal. The knee extensor at outset wasin some tonic contraction due to decerebrate rigidity. The reflex inhibition relaxesthis in addition to inhibiting the current reflex from the crossed foot. On returnof the reflex subsequent to its inhibition there is distinct increase in the height ofthe reflex contraction as compared with the height of contraction immediately priorto the
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