Effects of Needling Acupoint SI3 on Pressure Pain Threshold in Healthy Participants

Background: There has been a surge in prescribing opioids for pain-related conditions and it has resulted in a prescription "opioid epidemic." It is critical for researchers and clinicians to explore nonpharmacological approaches to manage pain and mitigate the reliance on opioid analgesics. Acupuncture could be an effective therapy to modulate pain. This study examined the effects on regional pressure pain threshold (PPT) following needling of the Small Intestine 3 (SI3 -Houxi) acupoint in healthy participants.Methods: In a randomized, three-arm cross-over design study, 32 healthy participants enrolled between November 2018 and March 2019, received 3 different acupuncture interventions, in different sequences, to the right hand at SI3: (1) SI3 without manual manipulation (SI3m-); (2) SI3 with manual needle manipulation (SI3m+); and (3) sham laser, to assess changes in PPT following the interventions. The mean change in PPT was measured at 10 different regional acupoint sites using an algometer. All PPT scores were reported as a percentage change from the mean preintervention value, the mean of the 3 PPT measurements obtained prior to receiving the intervention.Results: The SI3m+ and SI3m- interventions for the 31 participants (drop out <i>n</i>=1), showed that the postintervention mean % PPT scores were significantly elevated compared to the control (sham laser; <i>p</i> < 0.001). The SI3m+ intervention significantly increased % PPT compared with the SI3m- intervention (<i>p</i> < 0.001).Conclusion: The needling intervention was an important contributor raising regional PPT in healthy participants.