Cognitive Dual-tasking Augments Age-differences In Dynamic Balance While Walking On A Narrow Beam

Abstract

Beam walking is a measure of dynamic balance. We tested the idea that cognitive dual-tasking during beam walking could be an effective method to detect age-related differences in dynamic balance. PURPOSE: To determine the effects of age and cognitive dual-tasking on dynamic balance measured during narrow-beam walking. METHODS: 16 old (7M, 71.2 ±3.5 y, foot width: 9.2 ±0.5 cm, MMSE score ≥ 27) and 20 young (10M, 22.0 ±1.5 y, foot width: 9.3 ±0.8 cm) healthy volunteers participated in the study. Subjects walked on a 4-m long and 2-cm high beam with a width of 4, 8, and 12 cm, arms crossed in front of the chest. Subjects completed 3 walking trials with or without performing a calculation task. We recorded the gait trials from the subject’s right side with a digital video camera at 60 Hz, and computed walking distance, step number, and average step length. Average of 3 was used for the statistical analyses. RESULTS: There was a Group (old, young) by beam width (4, 8, 12 cm) by task (dual task, no dual task) interaction (F = 4.0, P < 0.05). In the young group, beam-walking distance decreased similarly with descending beam width while no dual-tasking (12 cm: 3.88, 8 cm: 3.62, 4 cm: 2.49 m) and dual tasking (12-cm: 3.87, 8-cm: 3.76, 4-cm: 2.59 m). In the old group, beam-walking distance decreased substantially and most in the narrowest beam width during no dual-tasking (12-cm: 3.85, 8-cm: 3.72, 4-cm: 1.46 m) but decreased extremely in both narrower widths during dual-tasking (12-cm 3.91, 8-cm: 2.63, 4-cm 0.66 m). Further, only in the old group, the distance walked was shorter while dual-tasking compared with no dual-tasking at 8 and 4 cm beam widths (both P < 0.01). Depending on beam width, step length decreased in the young while both step number and step length decreased in the old group. CONCLUSIONS: Beam width but not dual- tasking affected young adults’ dynamic balance whereas both beam width and dual-tasking affected substantially and interactively old adults’ dynamic balance as quantified by beam distance walked and stride properties. These results suggest that, if validated and cognitive performance also quantified, dual task beam walking could be a sensitive measure of dynamic balance and motor-cognitive function in aging. Supported by JSPS KAKENHI Grant Number 16K21320.