5. Limitation
pain
There were some limitations in this study. We did not investigate FR intensity. Also, FR intervention is typically not self-administered by patients, and this study has not been blinded. Future research should explore the effectiveness of self-administered FR intervention. In addition, all subjects were taking pain medication during the study period, but the time and dose after using the analgesic medication may vary among participants. Therefore, it is necessary to examine the time and dose after using the analgesic medication under uniform conditions in the future.