Multi-modal gait assessment in Parkinson's Disease: A pilot study examining the impact of terrain and environment

Impaired gait is common in people with Parkinson's disease (PwPD), increasing fall risk which is amplified when on complex/uneven terrains. Most studies focus on inertial-based spatiotemporal characteristics alone stratified to domains (e.g., pace) within indoor settings. Less is known about environmental challenges impacting joint kinematics and muscle activation, critical to understanding adaptive gait and informing personalised interventions. This pilot adopts a multimodal approach to examine the effects of different terrains and environments on gait in PwPD.

Ten PwPD completed indoor and outdoor walks across soft and hard terrains, including tiled rubber, rocky cobblestones, asphalt, grass, cobble pavement, and carpet. Spatiotemporal, knee joint kinematics, and muscle activation characteristics were collected via wearables. Multimodal characteristics were extracted by a previous validated data fusion methodology. Wilcoxon signed-rank test was used to investigate the impact of terrain and environment on gait.

Pace characteristics were significantly higher on hard terrain where their variability increased during outdoor walks. No significant differences were found in rhythm or asymmetry domains across terrain types or environmental contexts. Knee flexion-extension asymmetry was lower and peak flexion occurred earlier on hard surfaces. Muscle activation levels were significantly lower outdoors, while soft terrains produced higher activation in distal muscles during swing phases, although frequency measures tended to be higher on hard terrain. Terrain related differences were more limited compared to environmental differences in muscle activity.

Multimodal gait assessment using wearables can be conducted on PwPD in different settings. Findings demonstrate terrain and environmental demands influence spatial parameters, knee joint kinematics and muscle activity in PwPD which may be more informative for fall risk assessment and personalised interventions.