Motor Unit Abnormalities After Experimentally Induced Sensitization
Status:
Completed
Trial end date:
2020-03-10
Target enrollment:
Participant gender:
Summary
Central sensitization is a condition that represents a cascade of neurological adaptations,
resulting in an amplification of nociceptive responses from noxious and non-noxious stimuli.
This phenomenon presents itself in a vast majority of chronic pain syndromes. Previous
evidence has shown that central sensitization results in afferent nociceptor and dorsal horn
abnormalities; however, a link between whether this abnormality translates into motor output
and more specifically, ventral horn abnormalities, needs to be further explored. Twenty
participants were recruited and either a topical capsaicin or a placebo topical cream was
applied to their back to induce a transient state of sensitization. Surface
electromyography(sEMG) and intramuscular electromyography(iEMG) were used to record motor
unit activity from the trapezius and infraspinatus muscles before and after application of
capsaicin/placebo. Motor unit recruitment and variability were analyzed in the sEMG and iEMG
respectively