The Relationship between Balance Confidence and Center of Pressure in Lower-Limb Prosthesis Users

Abstract

Background: Agreement between the activities-specific balance confidence scale (ABC) and center of pressure (CoP) in prosthesis users is still very much unknown. The purpose of this study was to investigate the agreement between ABC and CoP in lower-limb prosthesis users. Methods: Twenty-one individuals with lower-limb prostheses were recruited. Participants were provided with the ABC scale and performed static balance tasks during eyes opened (EO) and eyes closed (EC) conditions whilst standing on a force platform. Pearson product moment coefficients between CoP displacements and ABC scores were performed. Participants were also stratified by those who had better (≥80 on ABC scale) and less (<80 on ABC scale) perceived balance confidence. Displacement was compared using an independent t-test with Cohen’s d to estimate effect size with alpha set at 0.05 for these tests. Results: There was a significant inverse moderate relationship between eyes opened displacement (EOD) (18.3 ± 12.5 cm) and ABC (75.1 ± 18.3%), r = (19)−0.58, p = 0.006, as well as eyes closed displacement (ECD) (37.7 ± 22.1 cm) and ABC, r = (19)−0.56, p = 0.008. No significant difference in EOD (t(19) = 1.36, p = 0.189, d = 0.61) and ECD (t(19) = 1.47, p = 0.156, d = 0.66) was seen between those with greater and less balance confidence. Conclusions: Self-report and performance-based balance outcome measures are recommended when assessing lower-limb prostheses users.