Study design
handedness
FOOT was a randomized double-blinded (participants and interpretation) prospective monocentric study. It was cross-sectioned so that each volunteer received both the intervention (foot reflexology—FR) versus the control (foot massage as a sham massage of FR—SM).The study was registered in ClinicalTrials.gov Identifier (NCT04661774—10/12/2020) after the study was approved by the French Ethic Committee (personal protection committee: CPP Ile de France III n°3827-RM) on September 08, 2020, and all methods were carried out in accordance with relevant guidelines and regulations. Then, all volunteers were included in the study between February and June 2021 after giving their written informed consent, in the ToNIC laboratory in Toulouse, France. The 30 volunteers completed the entire study.Healthy volunteers (n = 30) between 20 and 40 years old were included. All volunteers were right-handed, attested by a score superior or equal to 8/10 at the Edinburgh handedness inventoryRandomisation was established with the help of the MeDatAS unity from the Clinical Investigation Center (CIC) of Toulouse. Once included, participants were affected to a number and a group through a secure randomization interface via the CIC website. Volunteers were randomly split into two groups of 15. Group A received first the SM and secondly the FR; while group B received first the FR and secondly the SM, in order to see both the true FR and SM effects despite potential individual differences.After inclusion, resting-state functional MRI (rs-fMRI) acquisitions were done before (t0) and after (t1) the first intervention or control, depending on the group. The anatomical MRI (T1) acquisition was done in the middle of the cross-sectioned design, to be used as a washout time, that is a break time before the second intervention. Then, rs-fMRI acquisitions were again done before (t2) and after (t3) the second intervention or control, as opposed to the first time. Before and after each intervention and control, electrophysiological measures and a short interview about subjective well-being were done. Study design is presented in Fig. Study design. 