Physical Activity and Lower-Limb Strength in Relation to Static Balance with and Without Vision

Abstract

Background: Balance control relies on efficient sensory-motor integration, particularly when visual input is limited. While physical activity and muscular strength are known to enhance stability, the extent and gender-specific nature of these effects remain insufficiently understood. Objectives: This study aimed to investigate the influence of physical activity on postural control under visual deprivation and to examine its association with lower-limb muscular strength in healthy adults, accounting for gender differences. Methods: In this cross-sectional descriptive-analytical study, 86 healthy adults (55 men, 31 women; aged 35 - 60 years) were assessed. Physical activity was measured using the short form of the International Physical Activity Questionnaire (IPAQ-SF), static balance was evaluated with a force platform under eyes-open and eyes-closed conditions, and back and leg strength were measured using a dynamometer. Data were analyzed using Pearson correlation, linear regression, and independent t-tests. Results: Physical activity showed a significant negative correlation with postural sway in both visual conditions, indicating better balance with higher activity levels. Lower-limb strength correlated with balance only in the eyes-open condition. After adjusting for age, Body Mass Index (BMI), and strength, physical activity remained a significant predictor of balance performance. Men exhibited greater muscle strength than women, though no gender differences were found in balance outcomes. Conclusions: Regular physical activity and muscular strength are key contributors to postural stability, even under visual deprivation. These findings underscore the importance of incorporating activity-based and strength-oriented interventions into fall-prevention and balance enhancement programs.