Ellen N. Sutter, Katie J. Seidler, Ryan P. Duncan, Gammon M. Earhart, Marie E. McNeely
Program in Physical Therapy, Washington University School of Medicine, St. Louis, USA
DOI: 10.2340/16501977-2238

Objective: To evaluate the relationship between spatiotemporal parameters of forward and backward gait and quality of compensatory stepping responses in forward and backward directions in people with Parkinson’s disease with and without freezing of gait.
Design: Cross-sectional analysis.
Subjects: A total of 111 individuals with mild to moderate Parkinson’s disease.
Methods: Forward and backward gait velocity and step length were evaluated using a GAITRite walkway. Forward and backward postural responses were evaluated using items from the Mini Balance Evaluation Systems Test and the Movement Disorders Society Unified Parkinson Disease Rating Scale motor subsection. Relationships between gait and postural responses were examined for the full sample and for sub-groups with and without freezing of gait.
Results: There were significant (p < 0. 05) low to moderate correlations between postural responses and gait overall. Correlations were similar in the freezer and non-freezer sub-groups. Freezers performed worse than non-freezers on all gait parameters and backward postural response items (p < 0. 05).
Conclusion: Low to moderate relationships between gait and postural responses indicate the complexity of postural control and the potential involvement of different neural circuitry across these tasks. Better understanding of the relationships between gait and postural deficits in Parkinson’s disease may inform the future development of targeted interventions to address these impairments.

People with Parkinson disease often have impairments in how they move during walking and when responding to a loss of balance. Problems with walking and balance are often worse in people with Parkinson disease who experience freezing of gait, where they are unable to move their feet to take a step. We examined movement characteristics during responses to balance disruptions and also during walking in people with Parkinson disease who do and do not experience freezing of gait. Participants walked on an instrumented mat that measured walking speed and step length. Then, participants’ balance was tested using different clinical tests. We found that the relationships between the walking and the balance response measures were not very strong, and the relationships were similar in participants with and without freezing of gait. This suggests that walking and balance may be controlled by different brain mechanisms and may need to be assessed and treated separately in the clinical setting.