Visual perturbation training to reduce visual dependency in Parkinson’s disease: A randomized controlled trial
Remco J. Baggen, Anke Van Bladel, Maarten R. Prins, Jennifer Stappers, Joke Spildooren, Miet De Letter, Katie Bouche, Dirk Cambier, Leen Maes, Patrick Santens
Abstract
Decreased gait automaticity and increased visual dependency are important contributors to falls in people with Parkinson’s disease. The aim of this study was to assess if visual perturbation training during treadmill walking decreases visual dependency in people with Parkinson’s disease.
Introduction
Falls and fall-related injuries are a frequent and recurring problem in people with Parkinson’s disease (PwPD), with about 60% of PwPD falling at least once a year and up to 39% of fallers experiencing recurrent falls [1,2]. Fall-related injuries often lead to decreased mobility, independence, and quality of life [3–5].
Materials and methods
Subjects
For this randomized controlled trial, people with idiopathic PD were recruited through the Neurology Department of Ghent University Hospital, various physical therapy sites around Belgium, and via the Flemish Parkinson Ligue between 09/01/2023 and 18/04/2024. Initial eligibility criteria were age (50–67 years), a clinical diagnosis of early- to moderate stage idiopathic PD (Hoehn & Yahr [H&Y] scale I-III), and the ability to walk unassisted for at least 20 minutes.
Results
Initially, 29 participants were recruited. Four participants dropped out of the study after initial inclusion. Two participants (one VPT and one CONT) dropped out before training initiation due to injuries unrelated to the protocol. Two participants dropped out of the CONT group during training due to personal reasons and scheduling difficulties.
Discussion
To our knowledge, this is the first study to investigate the effects of VPT in combination with treadmill walking on visual dependency in PwPD. The main results of this single-blind randomized-controlled trial revealed that VPT can reduce visual dependency in early-stage PwPD, as well as improve temporal gait characteristics and cadence to a greater extent than treadmill training alone.
Conclusions
These results show that the capacity to decrease visual dependency and improve gait is preserved in PwPD, and indicate that VPT can be a viable rehabilitation approach to improve fundamental sensory and motor mechanisms associated with fall risk in PwPD. VPT resulted in significant reductions of visual dependency, primarily in early-stage PwPD. Improvements of temporal gait characteristics (i.e., stride- and swing time), and gait speed, but not in spatial characteristics (i.e., stride length and step width) suggest increased automaticity without alterations to overall motor strategies.
Citation: Baggen RJ, Van Bladel A, Prins MR, Stappers J, Spildooren J, De Letter M, et al. (2026) Visual perturbation training to reduce visual dependency in Parkinson’s disease: A randomized controlled trial. PLoS One 21(3): e0343223. https://doi.org/10.1371/journal.pone.0343223
Editor: Anne E. Martin, Pennsylvania State University Main Campus: The Pennsylvania State University - University Park Campus, UNITED STATES OF AMERICA
Received: August 12, 2025; Accepted: February 2, 2026; Published: March 2, 2026
Copyright: © 2026 Baggen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: The anonymised datasets generated and analysed for the current study are available via Zenodo: https://zenodo.org/records/17808873 under DOI https://doi.org/10.5281/zenodo.17808873.
Funding: This study was funded by a grant from the Flemish Parkinson League (Vlaamse Parkinson Liga) and the King Baudouin Foundation (Koning Boudewijn Stichting), grant number 2022-J1811020-226020. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
