Effects of Nine-Square Dance Performed on Soft Versus Hard Surfaces on Functional Mobility and Mean Arterial Pressure in Community-Dwelling Older Adults: A Randomized Controlled Trial

Functional decline in older adults can limit mobility, independence, and participation in daily activities. Nine square dance (NSD) is a simple exercise that may improve functional performance; however, the influence of the supporting surface remains unclear. This assessor-blinded randomized controlled trial compared the effects of NSD performed on a soft surface or nine square dance on soft surface (NSD-S) versus a hard surface or nine square dance on hard surface (NSD-H) in 114 community-dwelling older adults aged ≥65 years. Participants were randomly allocated to NSD-S or NSD-H and completed 45-min exercise sessions three days per week for three weeks, which were followed by a one-month self-directed exercise period. The primary outcome was the Timed Up and Go test (TUG). Secondary outcomes were the Five Times Sit-to-Stand Test (FTSST), 10-Meter Walk Test (10MWT), 6-Minute Walk Test (6MWT), and mean arterial pressure (MAP). Linear mixed-effects models demonstrated significant group × time interactions for TUG, the FTSST, the 10MWT, and the 6MWT (all p < 0.001). At week 3, immediately after the supervised intervention, the between-group difference in TUG changes favored NSD-S by −1.58 s (95% CI −2.22 to −0.95; p < 0.001). For MAP, a significant within-group reduction from baseline was observed in the NSD-S group at the one-month follow-up. However, the overall pattern of MAP change did not differ significantly between groups (group × time interaction, p = 0.850). These findings indicate that NSD performed on a soft surface produced greater short-term improvements in functional mobility, lower limb functional performance, walking speed, and walking endurance than the same supervised exercise performed on a hard surface, whereas no differential effect on MAP was demonstrated.