An examination, correlation, and comparison of static and dynamic measures of postural stability in healthy, physically active adults

Objective: To examine the relationship and differences between static and dynamic postural stability in healthy, physically active adults. Design: Descriptive laboratory study. Setting: Research laboratory. Participants: Ten females (age: 21.6 +/- 1.2 yrs. mass: 60.8 +/- 7.6 kg, height: 165.0 +/- 5.0 cm) and ten males (age: 25.1 +/- 3.0 yrs, mass: 73.9 +/- 8.7 kg, height: 173.5 +/- 9.0 cm). Main outcome measures: Static postural stability was measured during a single-leg standing task (standard deviation of the ground reaction forces). Dynamic postural stability was measured during a single-leg landing task using the Dynamic Postural Stability Index. Pearson's r-coefficients were calculated to examine relationships between the two tests and a one-way ANOVA was calculated to examine potential differences in test scores (p < 0.05). Results: None of the Pearson's r-coefficients achieved statistical significance. The one-way ANOVA and post hoc comparisons demonstrated that dynamic postural stability scores were significantly higher than static postural stability scores. Conclusions: A lack of a correlation between static and dynamic measures and increase in difficulty during dynamic measures indicates differences in the type and magnitude of challenge imposed by the different postural stability tasks. The more challenging dynamic measures of postural stability may be more suitable for prospective studies examining risk of ankle and knee injury in healthy, physically active individuals. (C) 2011 Elsevier Ltd. All rights reserved.