High-velocity insertion of acupuncture needle is related to lower level of pain.

Objectives: The aim of this study was to explore the effects of different acupuncture insertion velocities.

Design: This study was performed as a within-subject design to control for individual differences. The biomechanical properties of needle insertion and accompanying subjective acupuncture perception was compared between different insertion velocities.

Setting: The setting for this study was the laboratory of acupuncture meridian and functional neurology, Acupuncture and Meridian Science Research Center, Kyung Hee University.

Subjects: Sixteen (16) healthy volunteers participated in the study.

Intervention: An acupuncture needle was inserted to the acupoint LI4 by an acupuncture needle insertion device (ANI-KY) at high or low speed of needle insertion.

Outcome Measures: Biomechanical properties such as force and depth were measured online by sensors equipped with the ANI-KY device. Participants filled out a questionnaire about acupuncture sensation or perception.

Results: Acupuncture needle insertion at a higher velocity was linked with higher maximum power, lower level of pain, and de qi-like perceptions such as "compressing" and "heavy" (p<0.05).

Conclusions: These results suggest that needle insertion velocity might be a factor for controlling inadvertent pain during the acupuncture needling process and that biomechanical properties of needling may be related to acupuncture perception or sensation.