Effects of Mechanical Perturbations on Balance Control Strategies ‎during Walking in Active Older Adults

Introduction: Balance impairment VVCV s are a major contributor to fall risk in older adults. ‎Understanding how active older adults utilize balance control strategies under varying ‎perturbation intensities and directions can inform the development of effective rehabilitation ‎interventions. This study aimed to examine the hierarchical pattern of balance strategies in active ‎older adults exposed to mechanical perturbations.‎Methods: In this semi‑experimental study, active older adults were subjected to mechanical ‎perturbations at three intensities (low, moderate, high) and two directions (anterior–posterior, ‎mediolateral). Balance strategies—including ankle, hip, and stepping—were recorded using ‎video analysis and clinical observation. Data were analyzed using repeated‑measures ANOVA ‎and Bonferroni post‑hoc tests.‎Results: Perturbation intensity had a significant effect on strategy selection (p = ۰.۰۰۱). ‎Perturbation direction was also significant (p = ۰.۰۰۴), and the intensity × direction interaction ‎reached significance (p = ۰.۰۰۹). Ankle strategy predominated under low intensity, hip strategy ‎under moderate intensity, and stepping strategy under high intensity. Post‑hoc comparisons ‎confirmed significant differences between low vs. moderate (p = ۰.۰۱۲), moderate vs. high (p = ‎‎۰.۰۰۸), and low vs. high intensities (p = ۰.۰۰۱).‎Conclusion: Active older adults employ a hierarchical balance control pattern that shifts from ‎distal to proximal and finally to stepping responses as perturbation intensity increases. These ‎findings highlight the importance of perturbation‑based training, proximal muscle strengthening, ‎and reactive stepping exercises in rehabilitation programs aimed at reducing fall risk in older ‎adults.‎

کلیدواژه ها:

Active older adults ، balance control ، ankle strategy ، hip strategy ، stepping strategy ، mechanical ‎perturbation ، postural biomechanics