Postural Instability and Gait Impairment During Obstacle Crossing in Parkinson's Disease

Abstract Stegemöller EL, Buckley TA, Pitsikoulis C, Barthelemy E, Roemmich R, Hass CJ. Postural instability and gait impairment during obstacle crossing in Parkinson's disease. Objective To examine whether Parkinson's disease (PD) affects gait behavior and stability while walking over an obstacle. Design Parallel group comparisons were completed in which participants completed 5 trials of normal walking and 5 trials of obstacle crossing while gait kinematics and kinetics were collected. Setting University biomechanics laboratory. Participants Individuals with PD (n=10) and age- and sex-matched healthy older adults (n=10). Interventions Not applicable. Main Outcome Measures Gait parameters, obstacle clearance parameters, and center of mass motion were calculated during normal walking and obstacle crossing. Results Results revealed that decrements in gait performance in individuals with PD were amplified during obstacle crossing, suggesting that due to disease-related degradation, individuals with PD chose a more conservative strategy for obstacle crossing. Moreover, an increased duration of single limb support (18% increase), a decrease in anteroposterior range of motion (20% decrease), and an increase in mediolateral range of motion (36% increase, though not significant) coupled with the reduction in the distance between the center of pressure and center of mass (mean of 21% decrease across toe-off and heel strike) and increase in margin of stability (31% increase at toe-off and 71% increase at heel strike) may suggest that deficits in muscle strength and balance may contribute to this impairment. Conclusions Persons with PD alter their behavior to reduce the mechanical demands and increase dynamic stability during obstacle avoidance tasks.