Behavioral and neurological parameters of the nerve compression block

The nerve-compression block has been used to investigate movement control in the absence of kinesthetic information. Implicit is the assumption that tactile and kinesthetic sensation are eliminated 5 to 10 min. prior to motor function. Motor fibers in the ulnar and median nerves of the upper preferred limb were tested at systematic intervals throughout the duration of the block application. When kinesthetic cut-off was assigned, Ss performed three tapping trials with vision and audition eliminated. Progressive reduction in nerve-conduction parameters (motor nerve conduction velocity and amplitude of the muscle action potential) occurred across and below the block, with significant decrements occurring as early as 15 min. Results indicated that motor impairment was a confounding factor in the use of the nerve block technique.