RESUMEN
The reliability of outcome measures obtained using the Balance Master and the limits of stability in anterior, posterior, and lateral directions were evaluated in 70 healthy subjects aged 20 to 32 years. Data relating to static sway and the ability to shift the centre of gravity to preset targets were collected on three occasions one week apart. The centre of gravity position and limits of stability were determined over three trials and data converted from a relative reference system to absolute displacements from vertical. Intraclass correlation coefficients revealed fair to poor reliability of static and dynamic sway measures (coefficients < or = 0.55) and excellent reliability of limits of stability measures and the position of the centre of gravity (coefficients > or = 0.75). The variability in outcome measures from tests which do not maximally challenge the postural control system may be a hallmark of normal balance performance. Further, the intersubject variation in resting centre of gravity position and in limits of stability supports the use of absolute performance measures as the interpretive value of data expressed relative to standard norms is limited.
Asunto(s)
Equilibrio Postural , Postura , Adulto , Femenino , Humanos , Masculino , Evaluación de Resultado en la Atención de Salud , Rehabilitación/métodos , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: To determine the test-retest reliability and validity of data obtained using the Balance Master (BM), a computerized balance assessment and training tool. DESIGN: Data were collected on three occasions, 1 week apart. Intraclass correlation coefficients (ICCs) were calculated if significant (p < .05) between-subject variance was found using a univariate analysis of variance for repeated measures. Concurrent validity of the BM data was determined using the Berg Balance Scale and gait velocity as criterion standards. PARTICIPANTS: Twenty ambulatory hemiparetic subjects who had no history of lower extremity orthopedic problems, no neurological deficits apart from stroke, and had not trained using the BM. MAIN OUTCOME MEASURES: BM data relating to static and dynamic balance performance, gait velocity, and the total score from the Berg Balance Scale. RESULTS: ICCs indicated that only the BM test requiring subjects to shift their center of gravity to randomly highlighted targets (positioned in a circle representing 75% of the individual's limits of stability) was reliable, both in terms of movement path (ICC = .84) and movement time (ICC = .88). Concurrent validity of the BM data was established for the dynamic measures of balance only, which correlated with both the Berg Balance Scale and gait velocity outcomes (r > or = .48, p < .05). CONCLUSIONS: These findings suggest that in stroke patients the test-retest reliability of data obtained using the BM is greatest for complex tests of balance and that dynamic rather than static balance measures are valid indicators of functional balance performance.