Effects of External Factors on Stabilometric Measures of Postural Control

Abstract

Introduction . Postural stability is essential for reliable motor behavior; however, stabilometric measures may be influenced by sensory, cognitive, physical, and positional factors. Aim . To assess the effects of external factors on stabilometric measures of postural control in healthy individuals. Materials and methods . This pilot repeated-measures study included nine healthy volunteers (23.5 ± 0.5 years). Each participant completed nine tests: basic stance, single-leg stances, darkness, noise, cognitive and physical loads, smartphone use, and an additional-load condition. Six spatial and velocity center-of-pressure (COP) measures were recorded using a Kistler force plate, Qualisys Track Manager, and Visual 3D. Differences were assessed using the Friedman test followed by paired Wilcoxon tests with Holm correction. Results . A significant overall effect of experimental condition was found for all six measures (p < 0.001). The most consistent differences from basic stance were observed during single-leg stance: the left-leg condition differed in all measures and the right-leg condition in all except frontal range (pHolm = 0.031). A 7-kg load decreased COP path length (pHolm = 0.031). For cognitive load, darkness, noise, physical load, and smartphone use, most differences were not statistically significant after Holm correction. Conclusion . Stabilometric measures depend on testing conditions, with the most pronounced changes occurring when the support area is reduced. The protocol enables quantitative assessment of postural stability under different conditions. The small sample size and lack of normalization of the additional load to body mass limit generalization of the findings. Reliability, reproducibility, and practical significance require confirmation in a larger sample.