Older adults exhibit lesser smoothness despite increased caution than younger adults when navigating turns during...

Straight line walking currently dominates research into mechanisms associated with walking-related instability; however, the dynamics of everyday walking behavior are far more complex. The figure-8 walk test (F8W) is a clinically-feasible activity that focuses on turning mobility and provides a convenient and relevant task for understanding age-related differences in walking beyond our present knowledge of steady-state behavior. Our purpose was to investigate the effects of age (n = 30 older versus n = 31 younger adults) on path characteristics and the "smoothness" of turning mobility - herein measured via normalized center of mass jerk - during the F8W. Compared to younger adults, older adults completed the F8W with longer paths and slower speeds. We interpret this outcome to suggest that older adults adopt a more cautious strategy when navigating turns during walking than younger adults. In addition, older adults completed the F8W with increased jerk and thus lesser smoothness than younger adults. Thus, despite adopting what we view as a more cautious strategy of longer and wider paths, older adults have worse movement quality and thus perhaps lesser stability than younger adults during turning tasks critical to safe and effective community ambulation.