Postural, physiological and psychological reactions to challenging balance: does age make a difference?

Objectives: to determine if increases in balance challenge influenced concomitant change in self-efficacy, state anxiety and physiological arousal, and if these changes were correlated with changes in standing balance in young and older adults. Design: a 2 x 2 between- (age) by within-subject (balance challenge) factorial design. Setting: quiet standing trials were performed on low and high support-surface heights in a research laboratory. Subjects: 14 young (22-31 years) and 14 older (60-83 years) adults with no known neurological or balance disorders, or falls within the last year. Methods: forceplate-derived measures of standing balance, measures of state anxiety, blood pressure and task-specific balance and coping self-efficacy. Results: independent of age, mean position, amplitude and frequency of centre of pressure displacements were significantly influenced by surface height, as were anxiety and efficacy. Decreased amplitude and increased frequency changes observed in both age groups with increased balance challenge were consistent with a stiffening strategy. Blood pressure, state anxiety and self-efficacy were correlated with different postural control changes in young and older adults. Conclusions: older adults used the same stiffening strategy as young adults to cope with the increased anxiety and lowered confidence associated with standing on a high surface. Converging evidence indicates that physiological status, state anxiety and balance efficacy are related to specific changes in postural performance with increased balance challenge. Findings highlight the potential additive effects of psychological and physiological factors on clinical balance performance and the need to consider comprehensive rehabilitation and prevention techniques that concern psychological and physiological contributions to balance deficits.