Warm Qi Arrives after Tuina: Dose-effect Association between Number of Tuina and Warming Effect Measured Using Infrared Thermal Imaging

Background An increasing number of objective measurements are used to explore the dose-effect relationship of Tuina, but infrared thermal imaging has been rarely used. Objective To compare the temperature, muscle tone and pain threshold in the lesion area yielded by different times (3, 5 and 7) of Tuina with cross-palm pressing manipulation using infrared thermal imaging, providing a basis for the use of infrared thermal imaging to study the dose-effect of Tuina. Methods Eighteen patients with thoracic facet joint disorder (T3-T4) who visited Tuina Department, Guangdong Provincial Hospital of Chinese Medicine (Dade Road Main Hospital) from 17th June, 2021 to 24th December, 2021 were recruited and randomized into three groups by the number of Tuina with cross-palm pressing manipulation: 7-time group (n=6), 5-time group (n=6) and 3-time group (n=6). The infrared thermal imager was utilized to obtain a full body infrared thermogram, and extract the average temperature in the lesion area. The muscle tone of the erector spinae muscle adjacent to the affected thoracic vertebrae was measured by the tissue tension test. The pain pressure threshold of the site adjacent to paraspinal process of the affected thoracic vertebra was measured by the pain-threshold analyzer. Results After intervention, the temperature on the site 0.5 inch to the right spinous process of T3 (T3 R) or T4 (T4 R) in 3-time group decreased significantly (P<0.05). After intervention, there were statistically significant differences among the three groups in muscle tension on the site 0.5 inch to the left spinous process of T3 (T3 L) at 0.2 kg, T3 R at 0.2 kg, on the site 0.5 inch to the left spinous process of T4 (T4 L) at 0.2 kg, T4 L at 0.5 kg, T4 L at 0.8 kg, T4 R at 0.2 kg, or T4 R at 0.5 kg (P<0.05). The muscle tnsion of T3 R at 0.2 and 0.5 kg was higher significantly in 7-time group after intervention (P<0.05). The pain pressure threshold of T3 L, T3 R, T4 L, and T4 R was lowered significantly in 3-time group after intervention (P<0.05). The pain pressure threshold of T3 L and T3 R was lowered significantly in 7-time group after intervention (P<0.05). No adverse events were reported. Conclusion Fewer number of Tuina with cross-palm pressing manipulation may generate better improvement in clinical outcomes. Further research is required to explore the dose-effect of Tuina using the infrared thermal imaging, and our study may provide useful ideas for reference.