Postural instability and gait impairment during obstacle crossing in Parkinson's disease

To examine whether Parkinson's disease (PD) affects gait behavior and stability while walking over an obstacle.

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.

University biomechanics laboratory.

Individuals with PD (n=10) and age- and sex-matched healthy older adults (n=10).

Not applicable.

Gait parameters, obstacle clearance parameters, and center of mass motion were calculated during normal walking and obstacle crossing.

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.

Persons with PD alter their behavior to reduce the mechanical demands and increase dynamic stability during obstacle avoidance tasks.