The ischemic nerve block and skilled movement

Accuracy of skilled movement was investigated in a serial positioning task with the index finger reversibly deafferented by an ischemic nerve block. The reflex response to sudden muscle stretch was monitored at systematic intervals following cuff application. Serial positioning in the verified absence of stretch reflexes was significantly less accurate and more variable than under normal conditions. These findings were discussed in terms of the "servo-assistance" hypothesis for the control of movement and the limits of accuracy that can be achieved in the absence of kinesthesis.