The contribution of vision in dynamic spontaneous sways of male classical dancers according to student or professional level

We investigated the involvement of vision in the regulation of dynamic equi librium in male children and young adults performing a physical activity re quiring a high level of spatial skill: self-induced body sways of ballet da ncers on a free unstable platform, 45 professional male dancers (Paris Oper a) participated in the study. They included two student groups (beginners a nd confirmed) and two performer groups (adolescent and adult). They maintai ned their equilibrium on the platform under different visual and position c onditions. The displacements of the seesaw platform were calculated from ac celerometer measures. Fast Fourier transform processing of stabilograms all owed spectral frequency analysis. The total spectrum energy and the energie s of the three frequency bands (0-0.5 Hz, 0.5-2 Hz, 2-20 Hz) were determine d. For all groups, ANOVA indicated that values were higher for eyes-closed than for eyes-open conditions. The visual dependence differed according to age: for 14-year-old students the postural control for dynamic equilibrium was less visually dependent than for Ii-year-old students. The 18-year-old dancers, although professional, were more dependent on vision than 14-year- old student dancers. These 18-year-old dancers were still adolescent becaus e they had recently undergone growth acceleration which could disturb their proprioceptive references and internal body representations. Thus, visual input may dominate over the other sensory inputs in the regulation of postu ral control. (C) Elsevier, Paris.