RESUMEN
BACKGROUND: Foot baths are used in complementary and alternative therapy to improve the duration and quality of sleep and reduce tension, anxiety, fatigue, and confusion. They are also known to improve the frequency of labor contractions and to increase their duration in women; thus, they are commonly used by midwives in clinical settings in Japan. However, the physical and mental effects of foot baths during labor are unknown. OBJECTIVE: This study aims to assess the physical and mental effects of foot baths based on biomarker levels and self-administered questionnaires. METHODS: A single-arm pre-post test trial design is being used in this study, and the study is being conducted at a general hospital in Tochigi Prefecture, Japan. The target study population is women in the first stage of labor, the phase when the uterus starts to contract and when the cervix dilates to 10 cm, or those undergoing labor induction. Participants who meet the eligibility criteria are recruited, and written informed consent is obtained from them. They are asked to answer the questionnaire and to collect 1.5 mL of saliva in 2 microtubes each, before and after the intervention. The intervention is foot baths for 15-20 minutes using a foot bath device. Data on delivery, such as gestational age, gravidity, parity, diagnosis following the last vaginal examination, and presence or absence of membrane rupture, are retrieved from the medical records. The primary outcomes are salivary cortisol levels before and after the foot baths. The secondary outcomes are levels of relaxation and comfort, labor pain, body warmth, vital signs, and interval of labor pain before and after the foot baths, which are assessed using a numerical rating scale. A paired t test or Wilcoxon signed-rank test will be performed to compare the data for salivary cortisol levels and numerical rating scale scores. RESULTS: Data collection started on April 1, 2022. As of October 2022, we had enrolled 10 participants. Because of the COVID-19 pandemic in Japan, it is difficult for medical personnel to freely interact with women in labor until the results of the COVID-19 polymerase chain reaction test are available in the research facility, complicating the recruitment process. CONCLUSIONS: This is the first prospective study to assess the effects of foot baths using a biomarker during the first stage of labor. The findings on the effects of foot baths on women in labor will provide novel insights that may improve the outcomes of delivery. A randomized controlled trial to investigate the effects of foot baths to obtain robust evidence should be conducted in the future. TRIAL REGISTRATION: University Hospital Medical Information Network-Clinical Trial Registry UMIN000046539; https://tinyurl.com/2wwj7dns. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/39985.
RESUMEN
It has been recently suggested that contact with nature improves mood via reducing the activity of the prefrontal cortex. However, the specific regions within the prefrontal cortex that underlie this effect remain unclear. In this study, we aimed to identify the specific regions involved in the mood-improving effect of viewing images of nature using a 52-channel functional near-infrared spectroscopy (fNIRS). Specifically, we focused on the orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex (dlPFC), two regions associated with affective processing and control. In a randomized controlled crossover experiment, we assigned thirty young adults to view images of nature and built environments for three minutes each in a counterbalanced order. During image viewing, participants wore a fNIRS probe cap and had their oxyhemoglobin (oxy-Hb) measured. Immediately following each image viewing, participants indicated their mood in terms of comfortableness, relaxation, and vigor. Results showed that viewing images of nature significantly increased comfortableness and relaxation but not vigor compared to viewing images of built environments, with a large effect size. Meanwhile, the concentration of oxy-Hb in only the right OFC and none of the other regions significantly decreased while viewing the images of nature compared to built environments, with a medium effect size. We speculate that viewing images of nature improves mood by reducing the activity of or calming the OFC. Since the OFC is hyperactive in patients with depression and anxiety at rest, contact with nature might have therapeutic effects for them.