Performance variance on walking while talking tasks: theory, findings, and clinical implications

• Published in: AGE 2014-02, Vol.36 (1), p.373-381
• Main Authors: Holtzer, Roee, Wang, Cuiling, Verghese, Joe
• Format: Article
• Language: English
• Subjects: Accuracy; Aged; Aged, 80 and over; Aging; Attention - physiology; Biomedical and Life Sciences; Cell Biology; Dementia; Executive function; Executive Function - physiology; Female; Gait; Geriatrics; Geriatrics/Gerontology; Gerontology; Humans; Hypotheses; Life Sciences; Male; Medical research; Mental disorders; Mobility; Molecular Medicine; Mortality; Neuropsychological Tests; Neuropsychology; Older people; Paradigms; Parkinson's disease; Posture; Speech; Studies; Task Performance and Analysis; Walking; Walking - physiology
• ISSN: 0161-9152; 2509-2715; 1574-4647; 2509-2723
• DOI: 10.1007/s11357-013-9570-7

Dual tasks that involve walking and cognitive interference tests are commonly used in mobility assessments and interventions. However, factors that explain variance in dual-task performance costs are poorly understood. We, therefore, examined the moderating effects of two putative constructs, postural reserve and hazard estimate , on performance on a walking while talking paradigm. Participants were 285 non-demented older adults (mean age = 76.9 years; %female = 54.4). Postural reserve was operationalized as the presence or absence of clinical gait abnormalities. An empirical factor, based on measures of executive functions, served as a marker for hazard estimate. The moderation effects of postural reserve and hazard estimate on dual-task costs were examined via two-way interactions in a joint linear mixed effect model. Significant dual-task costs were observed for gait speed (95% CI = 30.814 to 39.121) and cognitive accuracy (95% CI = 6.568 to 13.607). High hazard estimate had a protective effect against decline in gait speed (95% CI = −8.372 to −0.151) and cognitive accuracy (95% CI = −8.372 to −0.680). Poor postural reserve was associated with reduced decline in gait speed (95% CI = −9.611 to −0.702) but did not moderate the decline in cognitive accuracy (95% CI = −3.016 to 4.559). Assessing postural reserve and hazard estimate can help improve mobility risk assessment procedures and interventions for individuals with cognitive and movement disorders.