ダンスを踊ろう -社交ダンスにおける姿勢制御カップル：プロとアマチュアのダンサーの違い

Assessing ballroom dancers as a pair rather than as isolated subjects provides a deeper insight into postural control mechanisms. The aim of this study was to evaluate postural sway in ballroom dancers by comparing the male partner, the female partner, and the dance couple in the standard dance position. Seven international standard ballroom dance couples and fourteen amateur dancers with three months of ballroom training participated voluntarily. Postural sway was assessed using two force plates. Subjects assumed a standard dance position preceded by a short dance phase and were instructed to hold the position for 30 s. Each trial was repeated twice. Center of pressure (COP) parameters were calculated for the anterior-posterior and medio-lateral planes, and a two-way mixed-design ANOVA was applied to assess group and positional effects Significant main effects of group (professional vs. amateur dancers) were found for COP parameters in both planes, with professionals showing higher range of COP (ra COP), root mean square of COP (rms COP), and velocity of COP (v COP) values (p ≤ 0.003, η²p = 0.20-0.50).The effect of condition (male, female, pair) was also significant for most COP variables (p ≤ 0.001, η²p = 0.15-0.41), with female dancers demonstrating lower v COP and Sample entropy (SampEn) values compared to males and pairs. No significant group × position interactions were observed in the anterior-posterior plane (p ≥ 0.06), whereas a significant interaction appeared in the medio-lateral plane for SampEn (p = 0.04, η²p = 0.15). Ballroom dance training influences postural sway. The female partner appears to stabilize the couple, while professional couples exhibit less regular COP signals, suggesting greater automation of postural control compared to amateurs.