Sensorimotor and neuropsychological correlates of force perturbations that induce stepping in older adults.
Inappropriate stepping in response to unexpected balance perturbations is more prevalent in older people and in those at risk of falling. This study examined responses to force-controlled waist pulls in young and older people, and sought to identify physiological and cognitive correlates of the force threshold for stepping. 242 older (79.7±4.2 years) and 15 young (29.5±5.3 years) adults underwent waist pull perturbations and assessments of physiological and neuropsychological functioning, general health and falls efficacy. Perturbation force that induced stepping, stepping strategy and number of steps were measured. The older group withstood less forceful perturbations with a feet-in-place strategy, compared to young. Likewise, older adults with high falls risk withstood less force than those with low risk. After controlling for body weight and gender, sway and lower limb strength were independent predictors of anterior stepping thresholds, reaction time was an independent predictor of posterior thresholds, and executive functioning and lower limb strength were independent predictors of the lateral thresholds. These results suggest that balance, strength and agility training, in addition to cognitive exercises may enhance the ability to withstand unexpected balance perturbations and reduce the risk of falls in older people.
Neuroscience Research Australia and The University of New South Wales, Sydney, NSW, Australia. d.sturnieks@neura.edu.au
Daina L
DL
Sturnieks
Jasmine
J
Menant
Jos
J
Vanrenterghem
Kim
K
Delbaere
Richard C
RC
Fitzpatrick
Stephen R
SR
Lord
D000058:Accidental Falls / Q000517:prevention & control; D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D000367:Age Factors; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000886:Anthropometry; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005684:Gait / Q000502:physiology*; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time; D012016:Reference Values; D012678:Sensation Disorders / Q000503:physiopathology; D012737:Sex Factors; D013647:Task Performance and Analysis