The effect of experimental pain on motor training performance and sensorimotor integration

Abstract

Sensorimotor integration (SMI) is the ability of the central nervous system (CNS) to integrate afferent (incoming) information from different body parts and formulate appropriate motor output to muscles. Effective sensorimotor integration is essential when learning new skills and when performing tasks at home and in the workplace (Rothwell &Rosenkranz, 2005). The overall aim of this thesis is to investigate the effect of acute experimental pain on sensorimotor processing. The primary outcome is the effect of acute experimental pain on somatosensory evoked potential (SEP) peaks. Secondary outcomes include the effect of pain on motor performance and the interactive effect of pain and motor training on SEP peaks. As expected for the placebo condition, no significant differences were found in any of the post-placebo peaks. Contrary to what was expected for the placebo condition, the only peak to be significantly different post-motor learning was the N24 peak. Contrary to what was expected, there were no significant differences for any of the peaks following capsaicin application. One of the secondary outcomes was the interactive effect of pain and motor learning on SEP peaks. The only peak to show any significant differences post-intervention/post-motor learning was the N24 peak. Another secondary outcome was the effect of pain on motor performance. In terms of accuracy, no significant differences were found for either condition following motor learning. However, the data does show a trend towards improved accuracy for the subjects in the intervention group while the subjects in the placebo show a trend towards decreased accuracy. As expected, there was a significant decrease in reaction time for both conditions post-motor learning. However, contrary to what was expected, reaction time decreased to a greater extent in the intervention condition as compared to the placebo condition. It was anticipated that the reaction time would decrease to a greater extent in the placebo condition as it was hypothesized that pain would negatively impact motor performance. It is suspected that the effect of the pain induced by the capsaicin made the motor training task more difficult and participants would have had to focus greater attentional resources to learn the task which lead to the enhanced performance following motor training.