No abstract

Exercise-induced muscle damage (EIMD) is characterized by pain, swelling, and shortening of the muscle; increased serum creatine kinase; decreased force output; and altered neuromuscular function. The aim of this study was to investigate the effects of EIMD to determine the relationship between the peripheral symptoms, neuromuscular changes, and delayed pain sensation during a submaximal movement of the biceps brachii on cortical alpha (α) activity. In contrast to the control (n = 12) group, the experimental (n = 16) group participated in an EIMD protocol, and both groups were monitored for 132 h post-EIMD protocol. At 12 h, neuromuscular functioning was already disturbed while the sensation of pain was perceived, but not fully developed. Muscle pain scores in the experimental group peaked after 36 h with the lowest torque reported at 12 h. α-1 activity increased significantly in the motor and somatosensory area 12 h post-EIMD while α-2 activity increased in the contralateral fronto-central area. At 36 h, pain had further increased and neuromuscular function improved while α-1 and α-2 activities had decreased. We hypothesize that α-1 activity over the motor and somatosensory cortex of the experimental group displays a compensatory increase in response to the changes in neuromuscular function during movement, while an increase in α-2 activity is related to the suppression of pain experienced within the first 12 h.

Exercise-induced-muscle-damage (EIMD) is a well-described phenomenon which leads to decreased force output and altered neuromuscular function. How these symptoms of EIMD affect brain function, in particular cortical activity has not been described. Therefore the aim of this study was to investigate the relationship between the symptoms of EIMD and cortical beta (β) activity during a submaximal biceps brachii movement. Half of the subjects participated in an EIMD protocol. Control and EIMD groups were monitored for 132h thereafter. Muscle pain scores in the EIMD group peaked after 36h with the lowest muscle torque reported at 12h. Beta-1 and -2 activity was increased in the frontal and parietal area in the experimental group at 12h. This suggests an impact of EIMD induced neuromuscular changes on the cortical proprioceptive and motor perceptive networks. Beta-2 activity decreased in the control group over time suggesting a loss in focused attention and greater familiarization with the protocol as the study progressed. These data suggest that a change in β-1 and -2 activity is associated with integrating movement perception and proprioception post-EIMD.