A measurement of the electrical excitability of a nerve or muscle, formerly used in the detection of damage to the motor nerves. Its use has largely been superseded by ‘electromyography, the direct recording of electrical activity in the muscles.
A number expressing the sensitivity of a nerve to electrical stimulation. It is the minimum duration, in milliseconds, during which a current of prescribed strength must pass through a motor nerve to cause contraction in the associated muscle. The strength of direct current (rheobasic voltage) that will just suffice if given an indefinite time is first determined, and exactly double this strength is used for the final determinations.