Gait Adaptability in Persons With MS Having Mild Disability

Overview

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of the central nervous system that frequently leads to walking impairment, balance deficits, fatigue, cognitive difficulties, and an increased risk of falls. Importantly, these problems can already be present in the early stages of the disease and may not be adequately captured by standard clinical walking tests, which primarily assess speed or distance. Such tests are often insufficient to reflect the complexity of real-life walking, which requires continuous adaptation to environmental challenges, and attention to internal and external stimuli. Gait adaptability, the ability to modify walking patterns in response to changing and unpredictable demands such as obstacles or sudden perturbations, is critical for safe mobility and fall prevention. Both proactive (anticipatory) and reactive (feedback-driven) gait adaptations are essential for maintaining balance and functional independence. However, gait adaptability and its underlying neural mechanisms remain insufficiently understood in people with MS. This study aims to provide a comprehensive assessment of gait adaptability in people with MS by evaluating both proactive and reactive gait adaptations using objective gait measurements and cortical activity recordings. The findings may contribute to the development of more sensitive outcome measures and inform targeted rehabilitation strategies that better reflect real-life mobility demands. Primary aims: • To investigate the behavioral measures and neural correlates of reactive and proactive gait adaptability in pwMS compared to HC Secondary aims: * To investigate factors related to gait adaptability * To investigate changes in gait adaptability during prolonged walking conditions

A total of 16 persons with MS will be recruited. In addition, 16 healthy controls, matched for age and sex, will be recruited for comparison. Participants will be recruited by researchers from the REVAL Research Center at Hasselt University using the REVAL website and social media platforms, as well as those of relevant organizations. Healthy control participants will be recruited via flyers and social media, with age- and sex-matching applied using a 5-year age range. The study consists of a single testing session. Outcomes will be recorded using time- and observation-based methods, and movement sensors will be used for motor performance tests, including the Timed 25-Foot Walk Test, Foot Tap Test, Heel Rise Test, 2-Minute Stepping Test, Six-Spot Step Test, and the 6-Minute Walk Test. Self-report questionnaires, including the Falls Efficacy Scale-International, Multiple Sclerosis Walking Scale, Modified Fatigue Impact Scale, Activities-specific Balance Confidence Scale, Gait-Specific Attention Profile, and Balance Recovery Confidence Scale, will be administered. The Mini-BESTest and cognitive tests, including SDMT and BVMT-R will be performed to assess balance and cognitive functions. Proactive gait adaptability will be assessed using an overground gait adaptability test (i.e., the Walking Adaptability Ladder Test). Participants will walk along a 10-meter walkway with stepping targets indicated by bars and rows that progressively decrease in size. They will be instructed to adapt their steps to the targets while walking at a fast pace. Three conditions will be performed, each lasting 20 seconds and repeated five times, with 15 seconds of rest between trials during which participants will stand upright. The conditions include walking with one step per target, walking with two steps per target, and a control walking condition consisting of usual walking over the 10-meter walkway at the fastest safe walking speed without running. Reactive gait adaptability will be evaluated using an instrumented augmented reality system (Computer Assisted Rehabilitation Environment Extended \[CAREN\]; Motekforce Link, The Netherlands). Twelve unannounced repetitive perturbations will be applied. The CAREN system is designed for biomechanical analysis of human movement and utilizes high-resolution recordings via a 3D motion capture system equipped with 18 Vicon cameras (Vicon Motion Systems, Oxford, UK). The dual-belt treadmill incorporates two embedded force plates and allows for self-paced speed adjustments. Clinically relevant spatiotemporal gait parameters and gait stability measures will be processed. Cortical brain hemodynamics will be assessed using functional near-infrared spectroscopy (fNIRS; NIRSport™, NIRx, Germany), composed of 16 sources and 16 detectors. The fNIRS cap will be worn during both proactive and reactive gait adaptability conditions.