Simple and dual task spatiotemporal gait measures can predict multiple falls in cognitively impaired older people, according to recent study results. However, the addition of a functional or cognitive secondary task did not help researchers better discriminate fallers from non-fallers with cognitive impairment.
“Cognitive impairment and dementia are known risk factors for falls, and the incidence of falls in older people with cognitive impairment is approximately double that of their cognitively intact counterparts. Underlying mechanisms for this increased risk are poorly understood and gait dysfunction may play an important role,” the researchers wrote. “To date, no studies have examined whether dual task gait abnormalities are associated with falls in community dwelling cognitively impaired older people or whether the addition of the secondary task provides additional benefit in discriminating fallers from non-fallers with this condition. The current study, therefore, investigated whether poor gait performance under simple, functional and cognitive dual task conditions increases the risk of falls in community dwelling older adults with cognitive impairment.”
Simple vs. dual task walking
Sixty-four older community dwelling individuals with mild to moderate cognitive impairment participated in six walking trials at their preferred speed under three conditions: simple walking, walking while carrying a glass of water in their preferred hand and walking while counting backwards from 30. Researchers measured spatiotemporal gait parameters using the GAITRite mat. Falls were recorded prospectively for 12 months.
At 12-month follow-up, 54% of participants reported falls, with 35% reporting multiple falls. Participants who fell multiple times walked more slowly, had shorter stride length, spent longer time in double support, had a wider support width and showed more variability in stride length and swing time, according to study results.
According to univariate analyses, participants walked with reduced gait speed, cadence and stride length, as well as with increased double support time, stride width, swing time variability and stride length variability while counting backwards compared with simple walking. While carrying a glass of water, participants walked with reduced gait speed, cadence and stride length and increased double support time and stride length variability. When researchers compared the two dual task conditions, results showed that participants walked with reduced gait speed and cadence and increased double support time, stride width and swing time variability while counting backwards compared with carrying a glass of water.
“Simple gait assessment is sufficient to predict falls in cognitively impaired older people. It may be that dual task gait is most beneficial in healthy cognitively intact older people, elucidating changes that simple gait assessment may not be able to detect,” Morag E. Taylor, BAppSc of the Falls and Balance Research Group at Neuroscience Research Australia and the University of New South Wales, both in Sydney, Australia, told O&P Business News.
“Performing more than one task whilst walking adversely affects gait in cognitively impaired older people. Dual task gait performance predicted multiple falls. However, simple gait assessment is sufficient in determining fall risk. Further research is needed to examine the benefit of gait training, including dual task training, with regard to reducing falls and fall-injury in this high risk population.”
In another study examining the relationship between falls and simple gait, Taylor and colleagues controlled for sensorimotor function and executive function in 64 community-dwelling cognitively impaired older people.
Overall, the relationship between gait and falls was mediated by sensorimotor function more than executive function. They found that sensorimotor function is more important than executive function in the complex relationship between gait performance and falls.
The researchers also examined the relationship between sensorimotor function and multiple falls in 165 cognitively impaired older people.
“In univariate analysis, hand reaction time, static balance on a compliant surface, leaning balance and overall fall risk score were significantly associated with multiple falls,” Taylor said. “In multivariate analysis, static and leaning balance were independently and significantly associated with multiple falls.” — by Casey Murphy
For more information:
Taylor ME. Gait Posture. 2013;37:126-130.
Disclosure: The Physiological Profile Assessment (FallScreen) is commercially available through Neuroscience Research Australia.