Age Differences in Postural Stability are Increased by Additional Cognitive Demands

TLDR

The study examined postural stability differences between younger (mean 57) and older (mean 77) volunteers. Participants stood on a force platform while completing five cognitive tasks (random digit generation, spatial memory, backward digit recall, silent counting, and counting backward in threes) and a no‑task control. Older adults showed poorer postural stability than younger adults across all conditions, with the age gap widening during spatial memory and backward digit recall tasks, and age remained a significant predictor after accounting for control stability, cognition, intelligence, and speed, indicating that visuo‑spatial working‑memory demands amplify age‑related stability deficits.

Abstract

We report an investigation of postural stability in two groups of volunteers (mean ages of 57 and 77). Participants were required to stand on a force platform while performing five cognitive tasks: (1) random digit generation, (2) Brooks' spatial memory, (3) backward digit recall, (4) silently counting from 1-100, and (5) counting backward in threes (aloud). There was also a control condition in which there was no cognitive task. Postural stability was adversely affected by age in all conditions. Moreover, the difference between the two age groups was significantly greater when performing tasks 2 and 3, in comparison with the age difference in the control condition. Regression analyses revealed that the effect of age on postural stability while performing these particular tasks remained significant even after the following measures were included in the regression: postural stability in the control condition, cognitive performance, intelligence, and speed. We suggest that age differences in postural stability are increased by cognitive tasks requiring use of the visuo-spatial sketchpad component of working memory.