Concurrent arm swing-stepping (CASS) can reveal gait start hesitation in Parkinson’s patients with low self-efficacy and fear of falling

Background: Movement incoordination, freezing of gait, fear of falling, low self-efficacy, and multi-tasking can all contribute to falls in Parkinson’s disease. How these multi-factorial risks interact in individual patients remain poorly understood. Methods: Concurrent arm swing-stepping is a simple motor test in which subjects are first asked to swing their arms before being instructed to initiate the secondary task of leg stepping-in-place. We postulated that in patients with multiple fall risks, sensorimotor impairments in upper- and lower-limb movement control can render concurrent arm swing-stepping a demanding dual task, thereby triggering gait hesitation. A total of 31 subjects with Parkinson’s disease were enrolled in the study. Results: It was found that concurrent arm swing-stepping induced hesitation primarily in Parkinson’s disease patients with low fall-related self-efficacy and a fear of falling. By contrast, concurrent arm swing-stepping led to limb incoordination in both patients and in healthy elderly controls. The calculated specificity and sensitivity of the concurrent arm swing-stepping test was 100 and 42 % for hesitation and 12 and 77 % for incoordination. Conclusion: These results suggest that the concurrent arm swing-stepping test can be used in conjunction with conventional psychometric assessments to facilitate multi-factorial assessment of potential fall risk