Effects of somatothermal far-infrared ray on primary dysmenorrhea: a pilot study

Abstract

The purpose of this study was to assess the beneficial effects of using a far-infrared (FIR) belt on the management of patients with primary dysmenorrhea. This is the first study to determine the efficacy of somatothermal FIR using a parallel-arm randomized sham-controlled and double-blinded design with objective physical evidence and psychometric self-reports. Fifty-one Taiwanese women with primary dysmenorrhea were enrolled in the study. Results indicate that there was an increased abdominal temperature of 0.6°C and a 3.27% increase in abdominal blood flow in the FIR group (wearing FIR belt) compared to those in the control group (wearing sham belt). Verbal rating scale and numeric rating scale scores in the FIR group were both lower than those in the control group. Compared to the blank group (wearing no belt), the average dysmenorrhea pain duration of the FIR group was significantly reduced from 2.5 to 1.8 days, but there was no significant difference in the control group. These results demonstrate that the use of a belt made of far-infrared ceramic materials can reduce primary dysmenorrhea.

Figure 1

The flow chart of participants through the trial.

Figure 2

The abdominal skin temperature distribution of pretest (a) and posttest (b) of applying an FIR belt.

Figure 3

The average increases in temperature after wearing the control belt and FIR belt. The symbol ** indicates a highly significant difference between groups using the Wilcoxon Signed-Rank Test.

Figure 4

The average increase in abdominal blood flow after wearing the control belt and FIR belt. The symbol * indicates a significant difference between groups using the Wilcoxon Signed-Rank Test.

Figure 5

The distribution of subjects' VRS scores on the first day of menstruation.

Figure 6

The distribution of subjects' NRS scores on the first day of menstruation.

Figure 7

The distribution of subjects' VRS scores on the second day of menstruation.

Figure 8

The distribution of subjects' NRS scores on the second day of menstruation.

Figure 9

The distribution of subjects' VRS scores on the third day of menstruation.

Figure 10

The distribution of subjects' NRS scores on the third day of menstruation.

Figure 11

The VRS scores on the first three days of menstruation. The symbols * and ** indicate a significant and highly significant difference between groups using the Wilcoxon Signed-Rank Test, respectively.

Figure 12

The NRS scores on the first three days of menstruation. The symbols * and ** indicate a significant and highly significant difference between groups using the Wilcoxon Signed-Rank Test, respectively.

Figure 13

The duration of menstrual pain presented by (a) a box-and-whisker plot and (b) a bar chart indicating the average and standard deviation. The symbol ** indicates a highly significant difference between groups using the Wilcoxon Signed-Rank Test.