Hiroki Sugiura^1,, Shinichi Demura², Tamotsu Kitabayashi³, Yoshimitsu Shimoyama⁴, Daisuke Sato⁴, Ning Xu⁵, Yuko Asakura⁶

Competitive swimmers may have inferior balance because antigravity strength exertion, which is used to stand, is not often necessary in the water. This study concerns the ability to stand with the manipulating and supporting legs and their laterality by examining 16 male competitive swimmers (age: 19.4±1.0 years, career: 13.7±2.1 years) and 16 male general university students (age: 20.6±1.2 years). Static balance and dynamic balance were evaluated by the center sway of foot pressure and stability on an unstable stool, respectively. The total path length, mean path length, maximal amplitude rectangle, root mean square area, and outline area for the former and the fluctuation index for the latter were selected as evaluation parameters. The results of a two-way ANOVA (group × leg) showed no significant difference in both the group and leg factors for static balance parameters. In contrast, the dynamic balance parameter showed a significant difference in both. Stability on an unstable stool was higher in the swimmer group than in the general student group and in the manipulating leg than in the supporting leg in both groups. In conclusion, dynamic balance while standing with the manipulating or supporting leg is superior in competitive swimmers, unlike static balance assessed by the center sway of foot pressure. In addition, dynamic balance in the manipulating leg is superior to that in the supporting leg for both groups.

static balance, dynamic balance, competitive swimmers