Walking impairment is highly prevalent in people with multiple sclerosis (pwMS) and is commonly monitored using spatiotemporal outcomes and performance tests (e.g., walking speed and endurance). However, these measures do not fully capture gait quality impairments, which can be defined as the biomechanical deviation of gait patterns from typical movement, including joint kinematics, joint kinetics, inter-joint coordination, asymmetry, and movement variability. Laboratory-based optical motion capture provides high-resolution methodologies to quantify these deviations and to support clinically meaningful interpretation.

To summarize the biomechanical alterations in gait identified through laboratory-based 3D gait analysis in pwMS, highlighting the most frequently reported biomechanical parameters and assessment protocols.

A systematic search of PubMed and Web of Science was performed (up to December 2025). Eligible studies included cross-sectional designs studies in English. Studies reporting only spatiotemporal parameters were excluded. Only studies using optical motion capture systems, with or without force platforms, were included.

Twenty-five studies met the inclusion criteria, a total of 1016 pwMS and 420 controls were included, with sample sizes ranging from 11 to 104 MS participants. Disability levels varied, with Expanded Disability Status Scale (EDSS) scores mostly ranging between 2.0 and 6.0. Across studies, gait deviations were most consistently identified at the ankle, followed by changes at the knee and hip, together with frequent asymmetry and increased variability. The most prevalent ankle abnormalities were reduced dorsiflexion during swing and at initial contact, and reduced plantarflexion at push-off, suggesting impaired foot clearance and reduced distal propulsion.

Gait in multiple sclerosis is characterized by reduced gait quality, with ankle dysfunction emerging as a key contributor, alongside altered coordination, asymmetry, and variability, despite substantial heterogeneity in study designs and acquisition protocols. Three-dimensional gait analysis provides a sensitive approach to detect clinically relevant impairments beyond conventional measures.