The study of the change of pressure and its relationship with the temperature inside the cup

Background: The cupping therapy is practiced widely in China. By observing the pressure and temperature changes inside the cup during the cupping therapy session, the relationship between these was studied to further the understanding of the therapeutic mechanism of cupping therapy. Methods: The research used a self-made 260ml glass cup equipped with both pressure and temperature probes that was applied to the lower back area (around BL23) of volunteers. The data of the tropical negative pressure and temperature change inside the glass cup was recorded during the 10 minutes cupping session using PowerLab data acquisition system. Results: The linear regression equation for both tropical negative pressure and temperature inside the cup during the 10-minute cupping session were Y = -0.13X-32.138, and the significant test for the regression coefficient was p ≥ 0.05, the high P value showed no statistically significant linear relationship between the tropical negative pressure and temperature inside the cup during the 10 minutes cupping session; in addition the correlation coefficient r = 0.04, and the coefficient of determination R²=0.002 also demonstrated that both variables had a weak linear relationship. Conclusion: The decrease in temperature was not the main factor for the changes of tropical negative pressure inside the cup during the cupping session. The main therapeutic mechanism of cupping was the mechanical stress created by the tropical negative pressure.