Balance confidence is associated with objective step-ascent movement kinematics in participants with age-related macular degeneration and glaucoma

Abstract

Purpose : To examine whether self-reported balance confidence and perceived risk of falling, relate to objective step-ascent movement kinematics in individuals with central and peripheral field loss, and similarly-aged controls

Methods : Ten participants with AMD (age: 77.9 ± 11.3), ten with glaucoma (71.6 ± 9.0) and nine control (71.9 ± 5.6) volunteers participated. The CONFbal (balance confidence) and Falls Self-Efficacy-International (FES-I; perceived risk of falling) questionnaires were administered. Participants were asked to ascend a single step while movement kinematics of both limbs were recorded using a 3D motion capture system. Visual acuity (VA), visual field (VF) and contrast sensitivity (CS) were assessed

Results : Visually impaired participants had significantly lower balance confidence than the control group (p =.03). No difference was found for perceived risk of falling. More interestingly, balance confidence correlated with several kinematic indices and VF scores. Specifically, lower balance confidence was significantly associated (p < .05) with: closer penultimate foot placement to the step (r =.51), slower lead toe crossing velocity (r =-.43), longer dual support duration before the step (r =.60) and on the step (r =.60), and longer total step duration (r =.61). Contrastingly, FES-I scores correlated only with trail toe crossing velocity (r =-.42).
Hierarchical regression analyses were performed to assess the association of the self-report measures with kinematic indices, while controlling for intercorrelations with demographic and vision variables. Separate analyses were performed for each kinematic index; age, group, VA, VF and CS were entered into step 1, and balance and perceived risk of falling were entered into step 2. The analyses revealed that self-report measures significantly predicted both step-duration (△R² = .12, p = .02) and dual-support on the step (△R² = .10, p = .02), over and above the influence of variables in step 1. Specifically, balance confidence positively predicted both step duration (β = .47, p = .04) and dual-support on the step (β = .58, p < .01), whereas the FES-I showed no associations

Conclusions : Certain objectively assessed step-ascent movement kinematics were associated with self-reported balance confidence, but not perceived risk of falling, suggesting the former to be clinically useful with VI patients

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.