Preliminary results of dancing exercise on postural stability in adolescent females

Twenty-six female student dancers of Chung-hua school of Art (mean age 17.5 +/- 0.5 years) and twenty-five healthy active female collegiate students (mean age 18.1 +/- 1.0 years) participated in this study to investigate the effects of dancing exercise on postural stability of adolescent female through a comparison study of two cohorts. The groups were matched in height and weight. Participants were excluded for left-side dominance, sustained lower extremity injury, any known vestibular system dysfunction, uncorrected visual problems, and other neurological conditions. Static and dynamic standing balances were measured by means of Biodex Stability System in six conditions include bilateral, dominant, and nondominant single leg stances with eye-open and eye-closed conditions. To investigate the difference between static and dynamic stabilities, two protocols were performed: the first protocol consisted of four positions including static position, Level 8, Level 4, and Level 1, respectively. They were instructed to maintain a level platform as stably as possible for a period of 30 seconds for each test and given a 30-second rest between tests. The second protocol was descending stability level that was gradually changed from Level 12 to Level 1 for 60 seconds. Balance indices included overall stability index, anterior-posterior stability index (APSI), and medial-lateral stability index. The results of first protocol showed that there were significant differences in overall stability index score between study and control groups at Level 8 with dominant single leg standing in the eye-open condition and the APSI score at Level 8 and at Level 4 with dominant single-leg standing in the eye-closed condition. There was no significant difference in the second protocol. The possible explanation is loss of familiarization adaptation because of level change consequently in both the groups, not step-by-step as in the first protocol study. Furthermore, a positive correlation was found between the dancing experience and the APSI at Level 8 and Level 4 with dominant single-leg standing in the eye-closed condition. In conclusion the findings implied that dancing exercise results in better postural stability and less visual dependence on postural control in adolescent females. Copyright (C) 2011, Elsevier Taiwan LLC. All rights reserved.