Differential Associations Between Distinct Components of Cognitive Function and Mobility: Implications for Understanding Aging, Turning and Dual-Task Walking

Functional Mobility and Its Relationship With Cognition in Older Adults With Normal Cognition, Motoric Cognitive Risk Syndrome, and Mild Alzheimer's Disease

BACKGROUND AND PURPOSE

Motoric cognitive risk syndrome (MCR) is a predementia syndrome and is a strong predictor of Alzheimer's disease (AD). Functional mobility, such as balance, sit-stand transitions, and turning, has not been clearly investigated in this population. This study aimed to compare functional mobility among older adults with normal cognition (NC), MCR, and mild AD. Cognitive-motor interactions were also investigated in all the groups.

METHODS

This cross-sectional study included 91 older adults, including 36 with NC, 32 with MCR, and 23 with mild AD. A battery of neuropsychology tests encompassing several domains, including general cognition, executive function, attention, episodic memory, visuospatial performance, and language, was administered, and functional mobility tasks, including the Short Physical Performance Battery (SPPB) and the Timed Up and Go Test (TUG), were also carried out. Differences between groups were analyzed with MANCOVAs (post hoc Bonferroni correction). Partial correlation analysis adjusted for age and education levels was used to examine correlations between functional mobility and cognitive function in each group. Canonical correlation analyses were used to determine the extent of the relationship between a set of cognitive variables (executive function, attention, and visuospatial performance) and a set of functional mobility variables (the SPPB and TUG) in the NC, MCR, and mild AD groups.

RESULTS AND DISCUSSION

The SPPB and TUG performance of the MCR and mild AD groups was significantly worse than that of the NC group. Visuospatial performance and depression were significantly correlated with functional mobility in the MCR group, while depression was the only specific cognitive aspect associated with functional mobility in the mild AD group. Canonical analysis demonstrated a significant relationship between cognition and mobility, explaining approximately 28.4% of the variance, in the NC group. However, the other two groups showed no significant correlation between cognition and mobility.

CONCLUSIONS

In addition to slow gait, deficits in sit-stand transitions and turning were also observed in the MCR and mild AD groups. We also found that motor-cognitive interactions may differ according to the level of cognitive impairment. Future studies should comprehensively assess functional mobility for different cognitive impairment populations.

The Science of Tai Chi and Qigong and Whole Person Health Part I: Rationale and State of the Science

The emerging paradigm of whole person health shares many core principles with traditional complementary and integrative health frameworks, including Tai Chi and qigong (TCQ). In the Fall of 2023, the Harvard Medical School Osher Center for Integrative Health hosted the inaugural international conference on The Science of Tai Chi for Whole Person Health: Advancing the Integration of Mind-Body Practices into Contemporary Health Care held at Harvard Medical School. A two-part white paper was written to summarize key conference topics, findings, and issues. Part I presented here summarizes the rationale for the conference and synthesizes the state of evidence for TCQ as rehabilitative and preventive tools for a range of clinical conditions, including falls and balance, cognition, mental health, sleep, cardiorespiratory health, musculoskeletal health, cancer, as well as translational evidence related to the neurophysiology, brain and immune function, and biomarkers of inflammation. The state of science of TCQ, viewed through the lens of traditional East Asian health constructs, is also discussed. Part II of this white paper outlines evidence gaps and opportunities and discusses strategies to address challenges in TCQ research, dissemination, and implementation.

A review of concurrent sonified biofeedback in balance and gait training

BACKGROUND

Sonified biofeedback is a subtype of auditory biofeedback that conveys biological data through specific non-verbal sounds. It can be designed to provide augmented biomechanical feedback in near-real-time when provided as "concurrent" biofeedback. As a practice that developed spanning across engineering and the arts, sonified biofeedback can extend beyond simple tones and beeps, towards more fully incorporating music in movement training. Sonified biofeedback may leverage the motivational aspects of music in movement training, the neuroplasticity benefits demonstrated from participation in music-based interventions, and neurological auditory-motor coupling, all while providing task-relevant cues to facilitate motor (re)learning. Sonified biofeedback may also provide similar benefits as rhythmic cueing (e.g., rhythmic auditory stimulation), or added benefits because sonified biofeedback does not impose a strict isochronous rhythm when it follows rhythms that are driven by outputs of the motor control system. In this review paper, the unique opportunity presented by concurrent sonified biofeedback as a movement training tool for balance and gait is introduced and discussed.

RESULTS AND DISCUSSION

This review paper brings together prior research from clinical, engineering, and artistic design sources using sonified biofeedback in balance and gait training across diverse end-users to highlight trends, reveal gaps in knowledge, and provide perspective for future work in the area. The goal was to review progress and critically assess research using sonified biofeedback during movement training for postural control or gait. 49 papers were selected based on their experimental investigation and statistical analyses of the effects of using sonified biofeedback to assist in movement training for feet-in-place balance tasks (20 papers) or gait tasks such as walking and running (29 papers). The sound design choices, experimental design features, and movement training results are summarized and reviewed. All but two studies reported at least one statistically significant positive effect of training with sonified biofeedback in biomechanical, clinical, or psychosocial measures. Conversely, only seven studies shared any negative effect on one biomechanical, clinical, or psychosocial measure (with five of these studies also reporting at least one other positive effect). After describing these encouraging findings, this review closes by sharing perspectives about future directions for designing and using sonified biofeedback in balance and gait training, and opportunities for more cohesive growth in this practice. One such suggestion is to pursue sonified designs and experimental designs that can translate to the neurorehabilitation field. This includes strategically selecting control groups and evaluation tasks to understand if improvements from training with one task transfer to additional relevant movement tasks. Additionally, it is important that future publications share details about the design processes and sound designs so researchers can more readily learn from one another.

CONCLUSIONS

Overall, this review shares the positive impact of using sonified biofeedback in balance and gait training. This review highlights the evidence of existing successes and potential for even more impactful future positive effects from using sonified biofeedback to help diverse populations with a spectrum of balance and mobility challenges and goals.

Intersession reliability of center of pressure measurement during bipedal standing with different count-back orders

INTRODUCTION

Dual-task assessments can identify changes in postural control during balance assessments. Static standing with backward counting is frequently used to evaluate postural control while dual-tasking. The most reliable countdown method for standing postural stability has not yet been defined.

RESEARCH OBJECTIVE

to investigate postural stability's intra- and inter-day reliability while backward counting in different steps.

METHOD

Thirty-nine healthy adults (20 females, 26.94 ± 7.55 years) completed 70 s trials of stability tests with no dual-task, counting backward under five conditions (in ones, tows, threes, fours, and fives) while standing on a force-plate in three sessions: two sessions were on the same day, and the third session was one-week apart. The repeatability of measurements was tested using repeated-measure analysis of variance, interclass correlation, and standard error of measurements.

RESULTS

The interclass correlation scores ranged from 0.67 to 0.92, and the standard error of measurements ranged from 2.9% to 13.4%. No significant systematic changes (p < 0.05) occurred between the testing sessions for any backward counting.

DISCUSSION

The backward counting showed higher reliability when performed in condition 5 (counting backward in five's). The inter-day reliability scores were greater than intera-day reliability.

CONCLUSIONS

Dual-tasking with most backward counting (in ones to fives) is reliable, and a quantitative assessment of the center of pressure could be used to monitor the changes in postural stability between sessions.

Effect of fear of falling on turning performance among patients with chronic stroke

BACKGROUND

Turning difficulties have been reported in stroke persons, but studies have indicated that fall history might not significantly affect turning performance. Fear of falling (FOF) is common after a fall, although it can occur in individuals without a fall history.

RESEARCH QUESTION

Could FOF have an impact on turning performance among chronic stroke patients?

METHODS

This cross-sectional study recruited 97 stroke persons. They were instructed to perform 180° and 360° turns, and their performance was represented by angular velocity. FOF was evaluated using the Falls Efficacy Scale-International (FES-I). Falls that occurred 12 months prior to the study assessment were recorded.

RESULTS

A higher FES-I score was significantly correlated with a decline in angular velocity in all turning tasks after adjustment for demographic data. The correlation remained significant after controlling for falls history. Participants with a high level of FOF exhibited significantly slower angular velocities during all turning tasks compared with those with a low level of FOF. Participants with a moderate level of FOF had a significantly slower angular velocity than did those with a low level of FOF during the 360° turn to the paretic side only.

SIGNIFICANCE

A higher level of FOF, regardless of fall history, was significantly associated with a reduced angular velocity during turning. A high level of FOF affected turning performance in all tasks. Turning performance may not be affected by fall experience. Anxiety about falling may have a greater effect on turning performance than does fall history.

Dual-task turn velocity - a novel digital biomarker for mild cognitive impairment and dementia

Background

Disorders associated with cognitive impairment impose a significant burden on both families and society. Previous studies have indicated that gait characteristics under dual-task as reliable markers of early cognitive impairment. Therefore, digital gait detection has great potential for future cognitive screening. However, research on digital biomarkers based on smart devices to identify cognitive impairment remains limited. The aim of this study is to explore digital gait biomarkers by utilizing intelligent wearable devices for discriminating mild cognitive impairment and dementia.

Methods

This study included 122 subjects (age: 74.7 ± 7.7 years) diagnosed with normal cognition (NC, n = 38), mild cognitive impairment (MCI, n = 42), or dementia (n = 42). All subjects underwent comprehensive neuropsychological assessments and cranial Magnetic Resonance Imaging (MRI). Gait parameters were collected using validated wearable devices in both single-task and dual-task (DT). We analyzed the ability of gait variables to predict MCI and dementia, and examined the correlations between specific DT-gait parameters and sub-cognitive functions as well as hippocampal atrophy.

Results

Our results demonstrated that dual-task could significantly improve the ability to predict cognitive impairment based on gait parameters such as gait speed (GS) and stride length (SL). Additionally, we discovered that turn velocity (TV and DT-TV) can be a valuable novel digital marker for predicting MCI and dementia, for identifying MCI (DT-TV: AUC = 0.801, sensitivity 0.738, specificity 0.842), and dementia (DT-TV: AUC = 0.923, sensitivity 0.857, specificity 0.842). The correlation analysis and linear regression analysis revealed a robust association between DT-TV and memory function, as well as the hippocampus atrophy.

Conclusion

This study presents a novel finding that DT-TV could accurately identify varying degrees of cognitive impairment. DT-TV is strongly correlated with memory function and hippocampus shrinkage, suggests that it can accurately reflect changes in cognitive function. Therefore, DT-TV could serve as a novel and effective digital biomarker for discriminating cognitive impairment.

Cognitive status is associated with performance of manual wheelchair skills in hospitalized older adults

PURPOSE

To examine the relationship between manual wheelchair skills and cognitive function in hospitalized older adults.

METHODS

The observational study included older adults who used a manual wheelchair following hip/knee surgery. Participants underwent a series of tests to evaluate manual wheelchair skills and cognitive performance. Four items appearing on the Wheelchair Skills Test: brake handling (locking/unlocking), a 10-metre forward roll, a 2-metre backward roll and rotating in place, were used to evaluate manual wheelchair skills. Cognitive function was evaluated by the Montreal Cognitive Assessment (MoCA), Trail Making Test (TMT), the Clock Drawing Test, and the Loewenstein Occupational Therapy Cognitive Assessment. The relationship between wheelchair skills and cognitive scores was assessed by a series of univariate linear regression analyses.

RESULTS

Fifty older adults, aged 65-85, participated in the study. The MoCA-7 (orientation) explained 19.3% of the variance related to the turn in place wheelchair skill, 18.8% of the variance related to the two-metre backwards roll and 31.9% of the variance related to the 10-metre forward roll. The addition of gender (to the MoCA-7) increased the explained variance related to the 10-metre forward roll and turn in place skills to 38.5% and 28.5%, respectively. As for the brakes handling skill test, gender explained 18.3% of the variance. The addition of the CDT (to gender) increased the explained variance for the brakes handling skill to 31.4%.

CONCLUSIONS

Because cognitive impairments negatively affect the performance of wheelchair skills, rehabilitation therapists may need to adjust wheelchair mobility training methods for cognitively impaired older adults.Implication for rehabilitationGiven the prevalence of older adults with cognitive impairments who use manual wheelchairs, it is critical to better understand the relationship between cognition and wheelchair skills.Poor results reported on the cognitive tests, specifically, visual attention and orientation, were found to be associated with poor performance of four manual wheelchair skills.Rehabilitation therapists should consider the cognitive status of older adults when teaching manual wheelchair skills, specifically in new users. Future studies should examine whether a customized preparation program, enhancing visuospatial orientation, can benefit manual wheelchair control in older adults.

Comparison of dual-task costs during different types of walking in people with Parkinson's disease: a controlled study

INTRODUCTION

Many of the activities in daily living require different walking skills such as straight walking (SW), walking with turning (WwT), curved walking (CW) or backward walking (BW) in a dual-task condition. However, there is a lack of evidence regarding the dual task cost (DTC) during different types of walking. Therefore, this study was planned to compare the DTC during different types of walking in people with Parkinson's disease (PwPD) and healthy controls.

METHODS

Thirty-one PwPD and 31 healthy controls were included. Different types of walking were assessed using the 10-Meter Walk Test for SW, the Timed Up and Go Test for WwT, the Figure-of-Eight Walk Test for CW, and the Three-Meter Backward Walk Test for BW. Walking assessments were performed in a single-task and a dual-task condition.

RESULTS

The DTC on SW was the lowest in both groups. The DTC on WwT, BW, and CW were similar in healthy controls, whereas the order of the DTC on remaining walking types from lowest to highest was; WwT, BW, and CW in PwPD. Also, the DTC on WwT, BW, and CW were higher in PwPD than healthy controls. However, the DTC on SW was similar in PwPD and healthy controls.

CONCLUSION

The DTC is different during SW, WwT, BW, and CW in PwPD. Therefore, walking type should be considered in studies investigating dual task walking in PwPD. Also, dual task exercises consisting of different types of walking should be included in rehabilitation programs of PwPD.

Functional topography of the neocortex predicts covariation in complex cognitive and basic motor abilities

Although higher-order cognitive and lower-order sensorimotor abilities are generally regarded as distinct and studied separately, there is evidence that they not only covary but also that this covariation increases across the lifespan. This pattern has been leveraged in clinical settings where a simple assessment of sensory or motor ability (e.g. hearing, gait speed) can forecast age-related cognitive decline and risk for dementia. However, the brain mechanisms underlying cognitive, sensory, and motor covariation are largely unknown. Here, we examined whether such covariation in midlife reflects variability in common versus distinct neocortical networks using individualized maps of functional topography derived from BOLD fMRI data collected in 769 45-year-old members of a population-representative cohort. Analyses revealed that variability in basic motor but not hearing ability reflected individual differences in the functional topography of neocortical networks typically supporting cognitive ability. These patterns suggest that covariation in motor and cognitive abilities in midlife reflects convergence of function in higher-order neocortical networks and that gait speed may not be simply a measure of physical function but rather an integrative index of nervous system health.

Balance performance and grip strength as predictors of cognitive function among community-dwelling older adults in the USA

Objectives

To investigate how balance and grip strength predicts the probability of cognitive function impairment (i.e., executive function: mild and mild-to-moderate impairment, and delayed recall) over eight years in community-dwelling older adults in the US, controlling for sex and race/ethnicity.

Methods

The National Health and Aging Trends Study dataset (2011 - 2018) was employed. Dependent variables included the Clock Drawing Test (Executive Function) and Delayed Word Recall Test. Longitudinal ordered logistic regression examined the association between cognitive function and predictors (i.e., balance and grip strength) over eight waves (n=9800, 1,225 per wave).

Results

Those who could complete side-by-side standing and semi-tandem tasks were 33% and 38% less likely to have mild or mild-to-moderate executive function impairment, respectively, relative to those who could not complete these tests. One score decrease in grip strength increased the executive function impairment risk by 13% (Odds Ratio: 0.87, CI: 0.79-0.95). Those who completed the side-by-side tasks were 35% (Odds Ratio: 0.65, CI: 0.44-0.95) less likely to experience delayed recall impairments than those who could not complete this test. With one score decrease in grip strength, the risk of delayed recall impairment was increased by 11% (OR: 0.89, CI: 0.80-1.00).

Conclusions

A combination of these two simple tests (i.e., semi-tandem stance and grip strength) can screen for cognitive impairment among community-dwelling older adults to identify people with mild and mild-to-moderate cognitive impairment in clinical settings.

Montreal cognitive assessment (MoCA) is highly correlated with 1-year mortality in hip fracture patients

Prevalence of cognitive impairment in hip fractures was 86.5%. MoCA is an independent risk factor of mortality. MoCA score of < 15 is correlated with 11.71 times increased risk of mortality. Early attention and caution should be given to these patients for appropriate intervention to decrease mortality rates.

INTRODUCTION

Hip fractures rank amongst the top 10 causes of disability and current mortality of hip fractures is high. Objectives were to determine 1) prevalence of cognitive impairment, 2) whether Montreal Cognitive Assessment (MoCA) score was an independent risk factor associated with mortality, 3) MoCA cut-off that result in high risk of mortality.

METHODS

This was a cohort study between July 2019 to June 2020. Inclusion criteria were 1) hip fracture, 2) >  = 65 years old, and 3) low-energy trauma. Patients undergo assessment for cognitive impairment with MoCA. Prevalence was assessed, MoCA cut-off point, and accuracy of statistical model was evaluated. Logistic regression modelling was used to assess association between mortality and MoCA.

RESULTS

There were 260 patients recruited. Two hundred twenty-five patients had MoCA score < 22 signifying cognitive impairment, and 202 patients had MoCA score of < 19. 46 hip fracture patients died at 1-year follow-up. 45 of these patients had MoCA score < 19, and 1 patient had a MoCA > 22. Results showed statistical significance and good model effect (at least 0.8) with MoCA cut-off points between < 15 and < 19 (p < 0.05). After controlling confounding factors, statistical significance still existed in MoCA cut-off point at < 15 (odds ratio (95% CI) = 11.71 (1.14, 120.71); p = 0.04).

CONCLUSION

Prevalence of cognitive impairment in hip fractures was 86.5%. MoCA is an independent risk factor of mortality in hip fracture patients. MoCA score of < 15 is correlated with 11.71 times increased risk of mortality at 1-year after a hip fracture. AUC with MoCA score < 15 was 0.948. Early attention and caution should be given to these patients for appropriate intervention to decrease mortality rates.

Effects of aging on cognitive and brain inter-network integration patterns underlying usual and dual-task gait performance

Introduction

Aging affects the interplay between cognition and gait performance. Neuroimaging studies reported associations between gait performance and structural measures; however, functional connectivity (FC) analysis of imaging data can help to identify dynamic neural mechanisms underlying optimal performance. Here, we investigated the effects on divergent cognitive and inter-network FC patterns underlying gait performance during usual (UW) and dual-task (DT) walking.

Methods

A total of 115 community-dwelling, healthy participants between 20 and 80 years were enrolled. All participants underwent comprehensive cognitive and gait assessments in two conditions and resting state functional MRI (fMRI) scans. Inter-network FC from motor-related to 6 primary cognitive networks were estimated. Step-wise regression models tested the relationships between gait parameters, inter-network FC, neuropsychological scores, and demographic variables. A threshold of p < 0.05 was adopted for all statistical analyses.

Results

UW was largely associated with FC levels between motor and sustained attention networks. DT performance was associated with inter-network FC between motor and divided attention, and processing speed in the overall group. In young adults, UW was associated with inter-network FC between motor and sustained attention networks. On the other hand, DT performance was associated with cognitive performance, as well as inter-network connectivity between motor and divided attention networks (VAN and SAL). In contrast, the older age group (> 65 years) showed increased integration between motor, dorsal, and ventral attention, as well as default-mode networks, which was negatively associated with UW gait performance. Inverse associations between motor and sustained attention inter-network connectivity and DT performance were observed.

Conclusion

While UW relies on inter-network FC between motor and sustained attention networks, DT performance relies on additional cognitive capacities, increased motor, and executive control network integration. FC analyses demonstrate that the decline in cognitive performance with aging leads to the reliance on additional neural resources to maintain routine walking tasks.

Dividing attention during the Timed Up and Go enhances associations of several subtask performances with MCI and cognition

We tested the hypothesis that dividing attention would strengthen the ability to detect mild cognitive impairment (MCI) and specific cognitive abilities from Timed Up and Go (TUG) performance in the community setting. While wearing a belt-worn sensor, 757 dementia-free older adults completed TUG during two conditions, with and without a concurrent verbal serial subtraction task. We segmented TUG into its four subtasks (i.e., walking, turning, and two postural transitions), and extracted 18 measures that were summarized into nine validated sensor metrics. Participants also underwent a detailed cognitive assessment during the same visit. We then employed a series of regression models to determine the combinations of subtask sensor metrics most strongly associated with MCI and specific cognitive abilities for each condition. We also compared subtask performances with and without dividing attention to determine whether the costs of divided attention were associated with cognition. While slower TUG walking and turning were associated with higher odds of MCI under normal conditions, these and other subtask associations became more strongly linked to MCI when TUG was performed under divided attention. Walking and turns were also most strongly associated with executive function and attention, particularly under divided attention. These differential associations with cognition were mirrored by performance costs. However, since several TUG subtasks were more strongly associated with MCI and cognitive abilities when performed under divided attention, future work is needed to determine how instrumented dual-task TUG testing can more accurately estimate risk for late-life cognitive impairment in older adults.

Do the dual-task "8-foot up and go" tests provide additional predictive value for early detection of cognitive decline in community-dwelling older women?

BACKGROUND

The 8-Foot Up and Go (8UG) test is a widely used mobility assessment. Some dual-task mobility assessments have been developed to help detect cognitive decline.

AIMS

This study developed a dual-task version of 8UG test to investigate the dual-task 8UG performance and to evaluate the ability of dual-task 8UG test in detecting cognitive decline.

METHODS

A total of 101 eligible community-dwelling women aged 60-74 years were grouped into the mild cognitive impairment group (MCI, n = 49) and the non-cognitive impairment group (NCI, n = 52). The 8UG tests under single-task (ST), manual dual-task (MT), and cognitive dual-task (CT) conditions were performed respectively. The dual-task cost (DTC) and the correct response rate (CRR) were calculated to quantify the dual-task interference.

RESULTS

Participants spent more time in performing the 8UG test under dual-task conditions. No differences were observed between NCI and MCI groups for 8UG parameters under ST and MT conditions (p > 0.05). When executing CT, significant differences were found in the number of correct answers and CRR (p < 0.05). CRR showed the strongest ability to predict MCI with a cut-off point of 0.50 (71.2% sensitivity and 61.2% specificity).

DISCUSSION

Both manual and cognitive dual-task were found to interfere with the 8UG performance. CRR with cutoff point of 0.50 could be a potential predictor of MCI in community-dwelling older women.

CONCLUSIONS

The CRR of the cognitive dual-task 8UG test could be recommended as a potential predictor for the early detection of MCI in community-dwelling older women.

Association Between Turning Mobility and Cognitive Function in Chronic Poststroke

Turning difficulties are common in patients with stroke. The detrimental effects of dual tasks on turning indicate a correlation between turning and cognition. Cognitive impairment is prevalent after stroke, and stroke patients with mild cognitive impairment had a poorer turning performance than did stroke patients with intact cognitive abilities. Therefore, we investigated the association between turning mobility and cognitive function in patients with chronic poststroke. Ninety patients with chronic stroke (>6 months post-stroke) were recruited. Angular velocity was assessed using wearable sensors during 180° walking turns and 360° turning on the spot from both sides. Global cognition and distinct cognitive domains were assessed using the Mini-Mental State Examination. In patients with stroke, turning mobility was significantly associated with global cognitive function and distinct cognitive domains, such as visuospatial ability and language. The balance function and lower limbs strength were mediators of the association between cognition and turning. The association highlights the complexity of the turning movement and dynamic motor and cognitive coordination necessary to safely complete a turn. However, our findings should be regarded as preliminary, and a thorough neuropsychological assessment to provide a valid description of distinct cognitive domains is required.

Measuring Achievement, Affiliation, and Power Motives in Mobility Situations: Development of the Multi-Motive Grid Mobility

The current study introduces the Multi-Motive Grid Mobility (MMG-M) in an age-stratified sample (N = 206) that aims to disentangle six motive components - hope of success, hope of affiliation, hope of power, fear of failure, fear of rejection, and fear of power - in mobility-related and mobility-unrelated scenarios. Similar to the classical Multi-Motive Grid (MMG), we selected 14 picture scenarios representing seven mobility and seven non-mobility situations. The scenarios were combined with 12 statements from the MMG. Both the MMG-M and MMG were assessed to allow comparability between psychometric criteria. The results of confirmatory factor analyses yielded a good model fit for a six-factor solution with an additional mobility factor for the MMG-M. Internal consistency of the items was similar to the MMG. Lastly, we investigated associations between the motive components and mobility-related variables. We found that risk awareness was positively related to all fear components in both mobility and non-mobility scenarios. Most importantly, physical constraint was positively associated with fear of rejection and fear of power in mobility situations underlining the importance to create support systems to reduce these concerns in people's everyday lives.

Associations Between Midlife Functional Limitations and Self-Reported Health and Cognitive Status: Results from the 1998-2016 Health and Retirement Study

BACKGROUND

Life-course approaches to identify and help improve modifiable risk factors, particularly in midlife, may mitigate cognitive aging.

OBJECTIVE

We examined how midlife self-rated physical functioning and health may predict cognitive health in older age.

METHODS

We used data from the Health and Retirement Study (1998-2016; unweighted-N = 4,685). We used survey multinomial logistic regression and latent growth curve models to examine how midlife (age 50-64 years) activities of daily living (ADL), physical function, and self-reported health affect cognitive trajectories and cognitive impairment not dementia (CIND) and dementia status 18 years later. Then, we tested for sex and racial/ethnic modifications.

RESULTS

After covariates-adjustment, worse instrumental ADL (IADL) functioning, mobility, and self-reported health were associated with both CIND and dementia. Hispanics were more likely to meet criteria for dementia than non-Hispanic Whites given increasing IADL impairment.

CONCLUSION

Midlife health, activities limitations, and difficulties with mobility are predictive of dementia in later life. Hispanics may be more susceptible to dementia in the presence of midlife IADLs. Assessing midlife physical function and general health with brief questionnaires may be useful for predicting cognitive impairment and dementia in later life.

Assessing a Sensory-Motor-Cognition Triad in Amnestic Mild Cognitive Impairment With Dichotic Listening While Walking: A Dual-Task Paradigm

A contemporary topic in aging research relates to the significance of cognitive changes proper to mild cognitive impairment (MCI) to higher risk of falls and gait deteriorations. The present study addresses this question in the amnestic type of MCI (aMCI) by examining a triad of interrelated comorbidities occurring in the MCI condition: attentional impairments, hearing loss and gait disturbances. To this end, we applied a dichotic listening (DL) test during over-ground walking. DL assesses spontaneous and lateralized auditory attention in three conditions (i.e., free report or Non-forced (NF), Forced-Right (FR) ear and Forced-Left (FL) ear). Earlier reports suggest that this dual-task paradigm evoke asymmetric gait effects on healthy controls, which are moderated by degree of hearing loss. Therefore, the aim of the present study was to evaluate the effects of DL on bilateral (data from both limbs) and lateralized (each limb separately) gait outcomes in a group of forty-three aMCI participants (mean = 71.19) and fifty-two healthy older controls (mean = 70.90) by using hearing loss as a covariate in all analyses. Results showed the aMCI group presented overall compromised gait parameters, especially higher gait variability in all DL conditions during lateralized attentional control. These findings were observed bilaterally, and no lateralized effects on gait were observed. Only after controlling for hearing acuity, gait asymmetries on step length variability emerged almost exclusively in healthy controls. It was concluded that hearing loss in the aMCI group together with higher attentional impairments preclude aMCI individuals to properly execute DL and therefore, they do not display gait asymmetries. The present data demonstrate that varied demands on attentional control dependent on hearing acuity affects gait negatively in healthy older adults and aMCI individuals in very different ways. The appearance of asymmetric effects seems to be a perturbation related to normal aging, while the lack of asymmetries but exaggerated gait variability characterizes aMCI. The present findings show the intricate interplay of sensory, cognitive, and motor deteriorations in different group of older adults, which stresses the need of addressing co-occurring comorbidities behind gait perturbations in individuals prone to develop a dementia state.

Effects of Exergame-Based Dual-Task Training on Executive Function and Dual-Task Performance in Community-Dwelling Older People: A Randomized-Controlled Trial

Objective: Aging is associated with decline in executive function that may lead to reduced dual-task performance. Regular exercise has been recommended for promoting or maintaining mental and physical health in older adults, yet only a fraction of older adults exercise regularly. Exergame training may have the potential to enhance exercise adherence. Therefore, the aim of this study was to examine the effects of exergame-based dual-task training on executive function and dual-task performance in community-dwelling older adults. Materials and Methods: This was a single-blinded, randomized-controlled trial. Twenty community-dwelling older adults were recruited and randomly assigned to one of two groups. All participants completed 36 trainings, including three 60-minute sessions/week over 12 weeks. Participants in the experimental group received exergame-based dual-task training, while those in the control group received home-based multicomponent exercise training. Measures of executive function, dual-task performance, and community walking ability were assessed before and after the intervention. Results: Significant group × time interactions (P = 0.000-0.027) with large effects were found in all selected outcome measures. Compared with the control group, the experimental group improved significantly in measures of general executive function (P = 0.014), inhibitory control (P = 0.037), cognitive dual-task performance (P < 0.001), and community walking ability (P = 0.002). Enhanced general executive function was highly correlated with either improved motor dual-task performance (r = 0.674) or improved cognitive dual-task performance (r = -0.701). Conclusion: These results suggested that exergame-based dual-task training improved both executive function and dual-task performance in older people. These positive effects could be transferred to enhance community walking ability. Clinical Trial Registration number: ACTRN 12617000095369.

Effects of cognitive workload on heart and locomotor rhythms coupling

Different physiological signals could be coupled under specific conditions, in some cases related to pathologies or reductions in system complexity. Cardiac-locomotor synchronization (CLS) has been one of the most investigating coupling. The influence of a cognitive task on walking was investigated in dual-task experiments, but how different cognitive tasks may influence CLS has poorly been investigated. Twenty healthy subjects performed a dual-task walking (coupled with verbal fluency vs calculation) on a treadmill at three different speeds (comfortable speed CS; fast-speed: CS + 2 km/h; slow-speed: CS-2 km/h) while cardiac and walking rhythms were recorded using surface electrodes and a triaxial accelerometer, respectively. According to previous studies, we found a cognitive-motor interference for which cognitive performance was affected by motor exercise, but not vice-versa. We found a CLS at the baseline condition, at fast speed in both cognitive tasks, while at comfortable speed only for the verbal fluency task. In conclusion, the cardiac and locomotor rhythms were not coupled at slow speed and at comfortable speed during subtraction task. Cognitive performances generally increased at faster speed, when cardiac locomotor coupling was stronger.

Turning assessment for discrimination of frailty syndrome among community-dwelling older adults

BACKGROUND

Frailty is a common geriatric syndrome and is characterized by decreased physiological reserve and increased vulnerability towards adverse health outcomes including falls. Turning is a challenging task and is reported to be one of the daily activities that leads to falling in older populations.

RESEARCH QUESTION

Does 180° walking turns and 360° turning on the spot differ among frail, pre-frail, and non-frail older adults? Can 180° walking turns and 360° turning on the spot cutoffs discriminate older adults with frailty from those without?

METHODS

A cross-sectional study was conducted on community-dwelling older adults aged over 65 years. Frailty was assessed using Fried's phenotype method, and turning tasks were measured by inertial sensors. The turn duration (s) and angular velocity (°/s) were recorded for analysis.

RESULTS

In total, 109 participants were enrolled including 50 pre-frail and 12 frail individuals. Frail older adults took significantly longer and had slower angular velocities to complete the 180° and 360° turning than did either pre-frail (p = 0.002 and p < 0.001, respectively) or non-frail (p = 0.03 and p < 0.001, respectively) older adults. Cutoff times of 2.45 and 3.46 s were found to best discriminate frail people from those without frailty in both the 180° (sensitivity 83.3 %, specificity 71.1 %, area under the receiver operating characteristic curve (AUC) 0.796) and 360° (sensitivity 91.7 %, specificity 74.2 %, AUC 0.857) turn tasks.

SIGNIFICANCE

Older individuals with frailty syndrome had difficulty turning as evidenced by a longer turning duration and a slower angular velocity. The turn duration could be a potential biomarker of frailty in older populations. Assessing the turning performance can facilitate early detection of the onset of frailty and inform early prevention and rehabilitation interventions in clinical practice.

Mobility impact and well-being in later life: A multidisciplinary systematic review

In modern societies, the understanding of how active mobility affects the elderly's psycho-physical well-being is crucial to design ageing-friendly transport measures. From a multidisciplinary perspective, this systematic review points out the mobility impact on three elements of the EU Active Ageing Index: health, independence and social connectedness. By scanning four databases (Scopus, Web of Science, PubMed, and TRID), 3727 peer-reviewed papers published in the last decade were found, of which 57 met the inclusion criteria. The screening process was conducted following the PRISMA protocol and registered to the database PROSPERO, while the quality assessment was done using the Mixed Methods Appraisal Tool. More than 80% of the papers showed that an active mobility prevents psycho-physical harms, while only few papers study the relation of mobility with independence and social inclusion, to reduce the need for assistance and the related public expenditures. The findings of this review give important information both to transportation researchers and policymakers and companies, underlining the need for further research as well as investments in targeted age-friendly transport systems. The Covid-19 emergency has further underlined the importance of this issue, being the elderly one of the more disadvantaged and frailer social group.

Tai Chi training's effect on lower extremity muscle co-contraction during single- and dual-task gait: Cross-sectional and randomized trial studies

BACKGROUND

Tai Chi (TC) mind-body exercise has been shown to reduce falls and improve balance and gait, however, few studies have evaluated the role of lower extremity muscle activation patterns in the observed benefits of TC on mobility.

PURPOSE

To perform an exploratory analysis of the association between TC training and levels of lower extremity muscle co-contraction in healthy adults during walking under single-task (ST) and cognitive dual-task (DT) conditions.

METHODS

Surface electromyography of the anterior tibialis and lateral gastrocnemius muscles was recorded during 90 sec trials of overground ST (walking normally) and DT (walking with verbalized serial subtractions) walking. A mean co-contraction index (CCI), across all strides, was calculated based on the percentage of total muscle activity when antagonist muscles were simultaneously activated. A hybrid study design investigated long-term effects of TC via a cross-sectional comparison of 27 TC experts and 60 age-matched TC-naïve older adults. A longitudinal comparison assessed the shorter-term effects of TC; TC-naïve participants were randomly allocated to either 6 months of TC training or to usual care.

RESULTS

Across all participants at baseline, greater CCI was correlated with slower gait speed under DT (β(95% CI) = -26.1(-48.6, -3.7)) but not ST (β(95% CI) = -15.4(-38.2, 7.4)) walking. Linear models adjusting for age, gender, BMI and other factors that differed at baseline indicated that TC experts exhibited lower CCI compared to TC naives under DT, but not ST conditions (ST: mean difference (95% CI) = -7.1(-15.2, 0.97); DT: mean difference (95% CI) = -10.1(-18.1, -2.4)). No differences were observed in CCI for TC-naive adults randomly assigned to 6 months of TC vs. usual care.

CONCLUSION

Lower extremity muscle co-contraction may play a role in the observed benefit of longer-term TC training on gait and postural control. Longer-duration and adequately powered randomized trials are needed to evaluate the effect of TC on neuromuscular coordination and its impact on postural control.

TRIAL REGISTRATION

The randomized trial component of this study was registered at ClinicalTrials.gov (NCT01340365).

Cognitive decline negatively impacts physical function

Many older adults report difficulty performing one or more activities of daily living. These difficulties may be attributed to cognitive decline and as a result, measuring cognitive status among aging adults may help provide an understanding of current functional status. The purpose of the present investigation was to determine the association between cognitive status and measures of physical functioning. Seventy-six older adults participated in this study; 41 were categorized as normal memory function (NM) and 35 were poor memory function (PM). NM participants had significantly higher physical function as measured by Short Physical Performance Battery (SPPB; 9.4 ± 2.2 vs. 8.4 ± 2.0; p = .03) and peak velocity (0.67 ± 0.16 vs. 0.56 ± 0.19; p = .04) during a quick sit-to-stand task. Dual-task walking velocities were 22% and 126% slower between cognitive groups for the fast and habitual trials, respectively when compared to the single-task walking condition. Significant correlations existed between measures of memory and physical function. The largest correlations with memory were for peak (r = 0.42) and average (r = 0.38) velocity. The results suggest a positive relationship between physical function and cognitive status. However, further research is needed to determine the mechanism of the underlying relationships between physical and cognitive function.

Spatial navigation and dual-task performance in patients with Dementia that present partial dependence in instrumental activity of daily living

BACKGROUND

Instrumental activities of daily living (IADLs) ability impairments are clearly related to cognitive and motor decline, as well as to the progression of Dementia. However, more low-cost assessments are necessary to better understand the process of IADL in patients with Dementia.

OBJECTIVE

To compare cognitive, motor and cognitive-motor performance at different stages of dependence on IADL in patients with Dementia.

METHODS

Dementia patients (n = 53, age range: 63-94) and healthy older adults (n = 39, age range: 62-97) were included, and those with Dementia were separated into IADL 1 (n = 18), IADL 2 (n = 17), IADL 3 (n = 18). All groups performed cognitive (Trail making test A, semantic verbal fluency, and Stroop test), motor (sit to stand, aerobic steps, and 8-foot up-and-go), and cognitive-motor tests (dual-task, and spatial navigation). One-way ANOVA, Kruskal-Wallis, and Bonferroni post-hoc tests were used to compare groups. Also, an effect size (ES) has been applied to evaluate differences among the dementia groups while the healthy older adults were used as a reference group.

RESULTS

Only cognitive-motor and cognitive tests showed significant differences among groups (IADL 1 x IADL 2 x IADL 3). Compared with the healthy group, the ES analysis exposed that patients in different stages of IADL showed the worst performance on tests combining motor and cognitive demand, but not for motor and cognitive function separately.

CONCLUSION

Poor dual-task and spatial navigation abilities are present in partial dependence in IADL, and these tasks should be considered as a functionality screening tool in patients with Dementia.

Intraindividual variability in neural activity in the prefrontal cortex during active walking in older adults

Intraindividual variability in gait and cognitive performance is distinct from central-tendency measures and associated with clinical outcomes in aging. Knowledge concerning intraindividual variability in neural activity, however, has been relatively scarce, and no research to date has reported on such variability during active walking. The current study addressed this major gap in knowledge. Participants were community-residing older adults (n = 394; mean age = 76.29 ± 6.65 years; %female = 55). Functional near-infrared spectroscopy (fNIRS) was used to measure oxygenated hemoglobin (HbO2) in the prefrontal cortex under three experimental conditions: single-task-walk, single-task-alpha (cognitive task), and dual-task-walk, which required the participants to perform the two single tasks simultaneously. Intraindividual variability in neural activity was operationalized using the standard deviation of fNIRS-derived HbO2 observations assessed during a 30-s interval in each experimental condition. The increase in intraindividual variability in neural activity in the dual-task-walk condition compared to both single-task conditions was associated with the presence of cognitive impairments and being a male. Furthermore, measures of intraindividual variability in neural activity and gait performance were positively correlated only under the dual-task-walk condition. Intraindividual variability in the neural activity of gait may be a novel marker for age-related impairments in mobility and cognitive function. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The use of Motor and Cognitive Dual-Task quantitative assessment on subjects with mild cognitive impairment: A systematic review

Dementia and Alzheimer's Disease (AD) represent a health emergency. The identification of valid and noninvasive markers to identify people with Mild Cognitive Impairment (MCI) is profoundly advocated. This review outlines the use of quantitative Motor and Cognitive Dual-Task (MCDT) on MCI, by technologies aid. We describe the framework and the most valuable researches, displaying the adopted protocols, and the available technologies. PubMed Central, Web of Science, and Scopus were inspected between January 2010 and May 2020. 1939 articles were found in the initial quest. Exclusion criteria allowed the selection of the most relevant papers; 38 papers were included. The articles, regarding four technological solutions "wearable sensors", "personal devices", "optokinetic systems", and "electronic walkways", are organized into three categories: "Quantitative MCDT", "MCDT Inspired by Neuropsychological Test", and "MCDT for MCI Stimulation". MCDT might furnish clinical landmarks, supplying aid for disease stratication, risk prediction, and intervention optimization. Such protocols could foster the use of data mining and machine learning techniques. Notwithstanding, there is still a need to standardize and harmonize such protocols.

How Dominant Hand and Foot Dexterity May Reveal Dementia Onset: A Motor and Cognitive Dual-Task Study

The combined provision of an arising number of dementia cases, and the substantial absence of effective treatments, led the scientific community toward the identification of early phases of this condition. Such an effort aims at the recognition of therapeutic windows and the characterization of the disease's different grades. In the last years, Motor and Cognitive Dual-Tasks (MCDT) have been widely used to address the early diagnosis of several neurocognitive disorders, among which dementia. Here we present different protocols: the walking MCDT, the toe-tapping MCDT, and the forefinger-tapping MCDT. Moreover, each task has been performed under different cognitive conditions: no cognitive effort, counting backwards by 1, 3, and 7. In this work, we report the results obtained through the combination of different motor and cognitive tasks, and we present 2 brand-new MCDT protocols, attempting to identify a sweet-spot for early diagnosis of dementia.

SPARC Metrics Provide Mobility Smoothness Assessment in Oldest-Old With and Without a History of Falls: A Case Control Study

Aging-related neuromuscular and neurocognitive decline induces unsmooth movements in daily functional mobility. Here, we used a robust analysis of linear and angular spectral arc length (SPARC) in the single and dual task instrumented timed up-and-go (iTUG) test to compare functional mobility smoothness in fallers and non-fallers aged 85 and older. 64 participants aged 85 and older took part in this case control study. The case group (fallers, n = 32) had experienced falls to the ground in the 6 months prior to the assessment. SPARC analyses were conducted in all phases of the single and dual task iTUGs. We also performed correlation mapping to test the relation of socio-demographic and clinical features on SPARC metrics. The magnitude of between-group differences was calculated using D-Cohen effect size (ES). SPARC was able to distinguish fallers during the single iTUG (ES ≈ 4.18). Turning while walking in the iTUG induced pronounced unsmooth movements in the fallers (SPARC ≈ −13; ES = 3.52) and was associated with the ability to maintain balance in the functional reach task. This information is of importance in the study of functional mobility in the oldest-old and to assess the efficacy of fall-prevention programs.

Executive function predicts decline in mobility after a fall: The MYHAT study

BACKGROUND

Evidence suggests that better cognitive functioning is associated with better mobility in older age. It is unknown whether older adults with better cognitive function are more resilient to mobility decline after a fall.

METHODS

Participants from the Monongahela Youghiogheny Healthy Aging Team (MYHAT) study were followed annually for up to 9 years for incident falls. We examined one-year (mean 1.0 year, SD 0.1) change in mobility pre- to post-fall using the Timed Up and Go (TUG) in relation to pre-fall cognition (executive function, attention, memory, and visuospatial function) among incident fallers (n = 598, mean age 79.1, SD = 7.0). Linear regression models tested the association of cognition with change in TUG. Interaction terms were tested to explore if age, sex, body mass index, physical activity, depressive symptoms, or visual acuity modified the associations of cognition and mobility among fallers. The association between cognition and one-year change in TUG was also tested in a comparison sample of non-fallers (n = 442, mean age 76.3, SD = 7.2).

RESULTS

Overall, mobility decline was greater in fallers compared to non-fallers. In fully-adjusted models, higher executive function, but not attention, memory, or visuospatial function, was associated with less decline in mobility among incident fallers. The effect was significantly stronger for those who were older, sedentary, and had lower body mass index. Higher scores in memory tests, but not in other domains, was associated with less mobility decline among non-fallers.

CONCLUSIONS

Higher executive function may offer resilience to mobility decline after a fall, especially among older adults with other risk factors for mobility decline. Future studies should assess whether executive function may be a helpful risk index of fall-related physical functional decline in geriatric settings.

Rahman MH, Mohammed Z, You YX. Incidence and Predictors of Cognitive Frailty Among Older Adults: A Community-based Longitudinal Study

(1) Background: Cognitive frailty (CF) is the simultaneous presence of physical frailty and cognitive impairment with an increased risk of dementia. Considering that the risk factors of CF are mostly elucidated from cross-sectional studies, we conducted a community-based longitudinal study to determine the incidence and the predictors of CF among Malaysian older adults.; (2) Methods: Out of 490 older adults participating in the Malaysian Towards Useful Aging (TUA) study, 282 were successfully followed-up at five-years for an analysis of the CF incidence. CF was defined as a comorbid physical frailty (>1 Fried criteria) and mild cognitive impairment (Petersen criteria). A comprehensive interview-based questionnaire was administered for sociodemographic information, cognitive function, physical function, dietary intake, psychosocial, and biochemical indices. Univariate analyses were performed for each variable, followed by a regression analysis to identify the predictors of CF that accounted for confounding effects between the studied factors; (3) Results: The incidence rate of CF was 7.1 per 100 person-years. Advancing age (OR=1.12, 95% CI:1.04-1.21, p < 0.05), depression (OR=1.20, 95% CI:1.05-1.37, p < 0.05), decreased processing speed, assessed by a lower digit symbol score (OR=0.67, 95%CI:0.0.56-0.80, p < 0.05), decreased functional mobility measured using Timed-Up-and-Go (TUG) (OR=1.23, 95% CI:1.04-1.46, p < 0.05), low vitamin D intake (OR:0.36, 95% CI:0.14-0.93, p < 0.05) and physical frailty (OR=2.16, 95% CI:1.02-4.58, p < 0.05) were predictors for CF incidence; and (4) Conclusions: Our study results could be used as an initial reference for future studies to formulate effective preventive management and intervention strategies to decelerate CF development among older adults.