Movement Does Not Promote Recovery of Motor Output Following Acute Experimental Muscle Pain

Abstract Objective To examine the effect of motor activity on the magnitude and duration of altered corticomotor output following experimental muscle pain. Design Experimental, pre-post test. Setting University laboratory. Subjects Twenty healthy individuals. Methods Participants were randomly allocated to a Rest or Movement group. The Rest group sat quietly without moving for the duration of the experiment. The Movement group repeated a unimanual pattern of five sequential keystrokes as quickly and as accurately as possible immediately following the resolution of pain. Pain was induced into the right extensor carpi radialis brevis muscle by a bolus injection of 0.5 mL hypertonic saline. Corticomotor output was assessed as motor evoked potentials in response to transcranial magnetic stimulation before, immediately after, and at 10, 20, and 30 minutes following pain resolution. Pain intensity was recorded every 30 seconds using an 11-point numerical rating scale. Results There was no difference in peak pain intensity (P