Effects of single-task versus dual-task training on balance performance in older adults: a double-blind, randomized controlled trial

Abstract

Objective: To compare the effect of 3 different approaches to balance training on dual-task balance performance in older adults with balance impairment.

Design: A double-blind, randomized controlled trial.

Setting: University research laboratory.

Participants: Older adults (N=23) with balance impairment (mean age, 74.8y). They scored 52 or less on the Berg Balance Scale (BBS) and/or walked with a self-selected gait speed of 1.1m/s or less.

Interventions: Participants were randomly assigned to 1 of 3 interventions: single-task training, dual-task training with fixed-priority instructions, and dual-task training with variable-priority instructions. Participants received 45-minute individualized training sessions, 3 times a week for 4 weeks.

Main outcome measures: Gait speed under single-task and dual-task conditions was obtained at baseline, the second week, the end of training, and the twelfth week after the end of training. Other measures, including the BBS and the Activities-specific Balance Confidence (ABC) Scale, were collected at baseline and after training.

Results: Participants in all groups improved on the BBS (P<.001; effect size [ES]=.72), and walked significantly faster after training (P=.02; ES=.27). When a cognitive task was added, however, only participants who received dual-task training with fixed-priority instructions and dual-task training with variable-priority instructions exhibited significant improvements in gait speed (P<.001, ES=.57; and P<.001, ES=.46, respectively). In addition, only the dual-task training with variable-priority instructions group demonstrated a dual-task training effect at the second week of training and maintained the training effect at the 12-week follow-up. Only the single-task training group showed a significant increase on the ABC after training (P<.001; ES=.61).

Conclusions: Dual-task training is effective in improving gait speed under dual-task conditions in elderly participants with balance impairment. Training balance under single-task conditions may not generalize to balance control during dual-task contexts. Explicit instruction regarding attentional focus is an important factor contributing to the rate of learning and the retention of the dual-task training effect.

Fig 1

Flow diagram of participant progress through phases of randomized controlled trial.

Fig 2

Bar graph of change (post testing - baseline) on self-selected walking speed under a dual-task condition (walking + mathematics task) by group (mean ± SE). Solid bar represents single-task balance training group (ST); lined bar represents dual-task training with fixed-priority instructions (FP); hatched bar represents dual-task training with variable-priority instructions (VP). Significant baseline to post intervention changes indicated by asterisk above bar. Group differences indicated by horizontal lines above bars.

Fig 3

Scatter plot with line of equivalence of self-selected walking speed under a dual-task condition (walking + mathematics task) before and after the training. Circle represents the single-task balance training group (ST); triangle represents the dual-task training with fixed-priority instructions (FP); rectangle represents the dual-task training with variable-priority instructions (VP). Any individual above the line of equivalence is a participant who improved after training.