Figure 1. Flowchart of the experimental design with the total sample. FSEO: firm surface, eyes open; FSEC, firm surface, eyes closed; CSEO: compliant surface, eyes open; CSEC: compliant surface, eyes closed; Tandem EO: tandem stance, eyes open; Tandem EC: tandem stance, eyes closed; SL R: standing on right foot only; SL L: standing on left foot only.