Motor control and proprioception
CEREBELLAR FUNCTION
To examine the motor control consequences of reduced cerebellar excitability after a fatiguing task, we quantified endpoint error during fast reverse-at-target goal-directed movements with the dominant index finger. We specifically chose this task because it requires the preplanned coordination of the antagonistic muscles, which relies heavily on cerebellar function (To examine the proprioceptive consequences of reduced cerebellar excitability after a fatiguing task, we quantified matching error during a position matching task with the dominant and nondominant index fingers. We specifically chose this task because proprioceptive acuity during active position matching tasks depends on the integrity of the cerebellum (For both tasks, the axis of rotation of the customized hand devices was in line with the axis of rotation of the metacarpophalangeal joint of the index fingers. We measured the displacement of the index finger using a low-friction potentiometer (SP22G-5 K, Mouser Electronics), located directly inferior to the metacarpophalangeal joints. The sampling frequency of displacement signals was 1000 Hz (NI-DAQ card, model USB-6009, National Instruments), and these signals were stored on a personal computer.