Quantification of the parameters of twisting–rotating acupuncture manipulation using a needle force measurement system

Background To date, much research has been conducted to measure needle manipulation quantitatively and objectively. This study was performed to quantitatively measure the differences in the amount of stimulation caused by various rotation frequencies and angles in twisting–rotating acupuncture needle manipulation. Methods The torque Z force exerted on a tissue was measured at various rotation frequencies and angles by rotating a needle with a needle force measurement system attached to a needle insertion tissue model. Results The results show that with rotation frequency at 60°, the torque Z force increased significantly from 0.023 N mm to 0.118 N mm as the rotation angle increased (p < 0.05). In addition, the torque Z force was significantly increased from 0.082 N mm to 0.292 N mm when the rotation angle increased from 60° to 180° at 0.15 Hz. (p < 0.05). A strong linear positive relationship between the torque Z force and rotation angle or frequency was obtained [Pearson correlation coefficient (r) > 0.88; p < 0.001]. Conclusion The change in needle–tissue interaction force by rotating angles showed a tendency to be higher than those by rotation frequency. Further quantitative research on various manipulations will be required for a standardized education on manipulation and stimulation as well as on needle model development to become possible.