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Background: Prior work suggests there may be greater reliance on executive function for walking in older people. The pre-frontal cortex (PFC), which controls aspects of executive function, is known to be active during dual-task walking (DTW). However, there is debate on how PFC activity during DTW is impacted by ageing and the requirements of the cognitive task., Research Question: Functional near infrared spectroscopy, was used to investigate how PFC activity during walking was affected by (i) healthy ageing; and (ii) dual-tasks that utilise inhibition or working memory aspects of executive function., Methods: Young (n = 26, 16 females, mean 20.9 years) and older (n = 26, 16 females, mean 70.3 years) adults performed five conditions: normal walking; Reciting Alternate Letters of the alphabet (RAL, requiring cognitive inhibition and working memory) during standing and walking; and serial subtraction by threes (SS3, requiring working memory alone) during standing and walking. Walking speed, cognitive performance, the PFC haemodynamic response, and fear of falling ratings were analysed using linear mixed-effects modelling., Results: Compared to quiet standing, PFC activity increased during normal walking for older adults but decreased for young adults (p < 0.01). Across both groups, fear of falling contributed to higher PFC activity levels when walking (p < 0.01). PFC activity increased during DTW, and this increase was greater when performing RAL compared to the SS3 task (p < 0.01). Although the rate of correct responses was higher for RAL, walking speed reduced more with RAL than SS3 in the young group (p = 0.01), and the rate of correct responses reduced more when walking with RAL than SS3 in the older group (p < 0.01)., Significance: Older adults have increased levels of PFC activation during walking compared to younger adults and fear of falling is a cofounding factor. The interference between gait and a concurrent cognitive task is higher when the cognitive task requires inhibition., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Research on the relationship between vestibular function and falls in older people is sparse. The perception of the postural vertical (PPV) provides an indicator measure of vestibular (otolith) function in the absence of visual input and diminished somatosensory feedback., Objective: This study examined whether impaired PPV is associated with falls in this group., Methods: One hundred and ninety-five people aged 70 plus years stood blindfolded on a motorised platform that could be tilted in the roll plane and attempted to adjust it so that their bodies were aligned to the vertical. Somatosensory feedback was minimised as the base and vertical support surfaces on the tilting platform were covered in thick soft foam rubber. PPV error from true vertical and PPV variability (°) were calculated. Participants also underwent an assessment of distal tactile sensitivity and the physiological profile assessment (PPA); fallers were defined as those who had one or more falls during a prospective 12-month follow-up period., Results: Eighty-eight participants (45%) reported falling in the follow-up year. Increased PPV error and variability were correlated with increased lateral sway in a condition of absent visual input and reduced foot somatosensory feedback (eyes closed/foam; r range = 0.16-0.20, p < 0.05) and with composite PPA fall risk scores (r range = 0.22-0.26, p < 0.05). PPV variability was a significant and independent predictor of falls after adjusting for the composite PPA scores, age and gender [adjusted RR = 1.42 (1.01-1.98)]., Conclusions: Older people with increased PPV variability are at increased risk of falls. These findings indicate that assessment of PPV may augment fall risk assessments in older people., (Copyright © 2012 S. Karger AG, Basel.)

Background: Older people often experience unusual sleeping patterns and a poor quality of night-time sleep. Insufficient sleep has potential effects on cognition and physical functioning and therefore may increase the incidence of falls in older people., Objectives: To determine the extent to which a range of physiological, psychological and health-related factors predict night-time sleep quality of older people living in self-care and assisted-care, and whether poor sleep quality is a risk factor for falls., Methods: 572 people, 81 men and 491 women (mean age 79.7 years, SD 6.4), recruited from self-care retirement villages and assisted-care hostels participated in the cross-sectional study with a subgroup of 169 followed up for falls for 1 year. The main outcome measures were sleep quality and prospective falls., Results: Approximately half of the sample rated their sleep quality as poor or fair. Many measures of health, medication use and mood were significantly associated with ratings of poor night-time sleep quality. Multiple regression analyses revealed poor circulation, use of psychotropic and diuretic medications, negative affect, pain, not having a friend in the village, lower fitness levels and daytime napping were significant and independent predictors of night-time sleep quality in both residential care groups. Napping daily was reported by 28% of the self-care group and 37% of the assisted-care group. Residents across both care levels who napped >30 min during the day, or reported <6 h sleep at night, were three times more likely to suffer multiple falls in the follow-up year when adjusting for health, medication and activity measures., Conclusions: Sleep disturbances were common and associated with a variety of psychological, physiological, health and lifestyle factors. Long daytime naps and short night-time sleep periods were associated with an increased risk of falls., (Copyright 2008 S. Karger AG, Basel.)

Background: Deterioration with age of physiological components of balance control increases fall risk. Avoiding a fall can also require higher level cognitive processing to select correct motor and stepping responses. Here we investigate how a competing cognitive task and an obstacle to stepping affect the initiation and execution phases of choice stepping reaction times in young and older people., Methods: Three groups were studied: young persons (YOUNG: 23-40 years, n = 20), older persons with a low risk of falls (OLR: 75-86 years, n = 18), and older persons with a high risk of falls (OHR: 78-88 years, n = 22). Four conditions were examined: choice stepping, choice stepping + obstacle, choice stepping + working memory task, and choice stepping + working memory task + obstacle. Step response and transfer times were measured for each condition, in addition to hesitant stepping, contacts with the obstacle and errors made in the memory test., Results: Older participant groups had significantly longer response and transfer times than the young group had, and the OHR group had significantly longer response and transfer times than the OLR group had. There was a significant Group x Secondary task interaction for response time (F(2,215) = 12.6, p <.001). With the memory task, response time was minimally affected in the YOUNG (7% increase, p =.11) but was slowed significantly in the OLR fallers (42% increase, p <.001) and more so in the OHR fallers (48% increase, p <.001). The obstacle had a small but significant effect on response time (9.4%) and a larger effect on transfer time (43.3%), with no differences among the groups. Errors in stepping, performing the secondary task and contacting the obstacle increased with age and fall risk., Conclusions: Compared with young people, older people, and more so those at risk of falling, have an impaired ability to initiate and execute quick, accurate voluntary steps, particularly in situations where attention is divided.