Minimum detectable change for single-leg-stance-time in older adults

Gait Posture. 2011 Apr;33(4):737-9. doi: 10.1016/j.gaitpost.2011.02.020. Epub 2011 Mar 27.


Introduction: Knowledge of real change values for clinical balance measures can guide clinicians and researchers in interpretation of change scores to evaluate the effectiveness of therapeutic interventions. We are not aware of studies that have reported minimum change values for single-leg-stance-time (SLST) in community-dwelling older adults. A measure of absolute reliability, the standard error of measurement (SEM), can be used to compute minimum detectable change (MDC), a clinically useful indicator of change in performance exceeding that attributable to measurement error. The purpose of this study was to quantify MDC for SLST in community-dwelling older adults.

Methods: Twenty-five adults (60-89 years) performed repeated trials of SLST. Relative and absolute reliability for SLST were quantified using the intraclass correlation coefficient and SEM. The MDC was computed from the SEM.

Results: SEM was 8.7 s and MDC at the 95% confidence level was 24.1 s for SLST. SLST exhibited large measurement error (40.8%) and high minimum change (113.1%) percent values.

Conclusion: Change in SLST performance should exceed 24.1 s to be considered real change. SLST exhibits poor absolute reliability and appears unlikely to be sensitive to detecting change in performance in geriatric clinical settings and research studies.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Male
  • Middle Aged
  • Postural Balance / physiology*