Unilateral postural control of the functionally dominant and nondominant extremities of healthy subjects

To determine whether a difference in unilateral postural stability exists between the functionally dominant and nondominant legs of a healthy population.

The unilateral postural control of both legs of healthy subjects was tested using a force plafform. Before the postural control examination, each subject performed a series of functional tests to determine functional leg dominance.

Ten healthy young adults with a mean age of 19.2 +/- 3.2 years volunteered for this study.

Functional leg dominance was determined through the use of a battery of tests that included 3 separate evaluations of lower extremity dominance for functional activity. Two measures of postural control, sway area (SA) and sway path length (SPL), were collected for both the dominant and nondominant legs of all subjects. An analysis of variance (ANOVA) was used to determine whether a difference in postural control between the 2 legs was present.

A subject x leg repeated-measures ANOVA was conducted on both dependent variables, SA and SPL. The SA ANOVA value was not significant. The mean value for the dominant-leg SA measurement was 9737.43 +/- 303.36 mm(2), whereas the mean SA for the nondominant leg was 9431.74 +/- 349.97 mm(2). The SPL ANOVA also showed no significant difference in the bilateral comparison. The mean SPL for the dominant leg was 4321.57 +/- 630.0 mm, and the mean SPL for the nondominant leg was 4341.88 +/- 1,013.31 mm.

We found no difference in unilateral postural stability between the functionally dominant and nondominant lower limbs in a healthy population of young adults. This is of particular interest to the clinician who commonly uses singleleg postural control evaluations in the assessment of an athlete's level of progress in the rehabilitation setting.