Age-Related Differences During Single and Multi-Task Walking

Biologic aging is characterized by cognitive and somatosensory deteriorations resulting in gait modifications. Thus, the purpose of this study was to investigate the effects of cognitive (Cl) and/or motor interference (MI) tasks on gait velocity in young and old adults. Thirty-six healthy young (n = 18, age 22.3 +/- 3.0 years, BMI 21.0 +/- 1.6 kg/m(2)) and old sub-jects (n = 18, age 73.5 +/- 5.5 years, BMI 24.2 +/- 1.6 kg/m(2)) participated in this study. Cognitive functions were tested by means of the "Mini-Mental-State" and the "Clock-Drawing-Test". Gait velocity was measured on a pressure sensitive instrumented walkway (GAITRite system) under single-task (walking), dual-task (walking + CI/MI) and triple-task conditions (walking + Cl + MI). Irrespective of task condition, elderly subjects walked slower than young subjects (p < .001, in all conditions). Gait velocity was reduced in both age groups with increasing task complexity (p <= .002, in both groups). Larger reductions in gait velocity under multi-task conditions in old compared to young adults indicate that the regulation of gait is less automated in old age, i.e. more attentional resources are required. Given the implications of walking under multi-task conditions in everyday life, it is suggested that functional mobility in general and gait velocity in particular should be assessed under multi-task conditions in older adults.