The effect of obstacle crossing on interjoint coordination and variability in gait of individuals with Parkinson's disease

Understanding the impact of obstacle crossing on inter-joint coordination and variability in the gait of individuals with Parkinson's disease (PD) is critical for the development of effective rehabilitation strategies. The aim of this study was to investigate the effect of obstacle crossing on inter-joint coordination and variability in the gait of individuals with Parkinson's disease. A motion capture system recorded kinematic gait data in two conditions - normal gait and obstacle crossing - in 15 individuals with Parkinson's disease (8 males and 7 females) and 17 healthy age-matched controls (9 males and 8 females). The vector coding technique was employed to evaluate coordination and its variability for the Knee-Hip, Ankle-Hip, and Ankle-Knee joint pairs during gait and obstacle crossing. A significant difference was observed between the two groups in joint coupling angles during the loading response and push-off phases (p < 0.05). Obstacle crossing induced phase and coupling angle changes between joints in both groups (p < 0.05), but only in the PD group, it resulted in increased variability in the ankle-knee coupling angle during the push-off phase (p < 0.05). The PD group exhibited lower variability during normal gait and higher variability during obstacle crossing compared to the control group (p < 0.05). Parkinson's disease alters joint angles, leading to changes in joint coupling angles and phase coordination between joints. Moreover, the level of variability in joint coupling angles, particularly during the loading response and push-off phases, is influenced by Parkinson's disease.