(303) Does Pain-Inducing Massage Produce Pain Sensitivity Changes Similar to a Conditioned Pain Modulation Paradigm? A Double-Blinded Randomized Controlled Trial

Abstract

Massage is analgesic for some people with pain-inducing massage (PIM) resulting in greater pain sensitivity changes compared to pain-free massage (PFM). However, the underlying neurobiological mechanisms are not well-understood. Given that the experience of pain and analgesia rely on the functioning of pain inhibitory systems, PIM may exert analgesia via mechanisms consistent with conditioned pain modulation (CPM). Thus, we aimed to determine if PIM used as a conditioning stimulus would result in comparable self-reported and experimental pain sensitivity changes as a cold pressor task or a PFM control. Fifty healthy participants (68% female, mean age 22 years (SD=4.72)) were randomly assigned to four, one-minute exposures to a cold pressor to the hand, a PIM or PFM to the neck. Pressure pain thresholds (PPT) were assessed on the contralateral foot before and after each intervention period. Cold pressor pain ratings (M=39.78, SD=24.43)) exceeded PIM pain reports (M=22.04, SD= 14.54, p 0.05). Pearson correlation revealed that greater intervention-related pain was associated with increases in PPT (r=0.29, p=0.04). Although PIM resulted in less self-reported pain than a cold pressor task, both resulted in similar magnitude of the CPM response suggesting shared underlying mechanisms. Future studies are needed to elucidate the neurobiological substrates of PIM that can help identify therapeutic outcomes.