Interaction of age, cognitive function, and gait performance in 50-80-year-olds

Prevalence of cognitive impairment and associated factors in older people

BACKGROUND

Older people are the fastest-growing age group, with the highest risk of cognitive impairment. This study assessed the prevalence and associated factors with cognitive impairment in community-dwelling older people.

METHODS

Older people were interviewed and accomplished through sociodemographic and health questionnaires. The quantitative variables were described by mean and standard deviation or median and interquartile range. The significance level adopted was 5 % (p < 0.05). The association between the quantitative variables was evaluated using the Pearson or Spearman correlation coefficients.

RESULTS

The research population comprised 165 long-lived adults aged ≥80. The youngest one was 80, and the oldest one was 94 years old. The participants were 84.8 ± 3.6 years old, female (63 %) with a mean of education of 2.9 ± 1.8 years. A poor performance in the Mini-Mental State Examination (MMSE) was found in 58 (35.2 %) individuals when adjusted for educational level. After adjustment for confounding factors, body mass index (BMI) (p = 0.09), total older adults' income (up to 1 minimum wage [mw], p = 0.023; over 1 to 2 mw, p = 0.023), functional disability (Moderate dependence 75 %, p = 0.038; Moderate dependence 50 %, p = 0.081; Moderate dependence 25 %, p = 0.054), and the anxiety scale (p = 0.032), remained associated with cognitive impairment.

CONCLUSIONS

This study showed that BMI, total older adults' income, functional disability, and anxiety are related to cognitive impairment in long-lived adults. This study has some limitations, such as the fact that it is a cross-sectional study, the reduced number of individuals, and the fact that there were no comparisons among different ages and populations.

Exploring the effects of dopamine on sensorimotor inhibition and mobility in older adults

Dopaminergic activity decreases in older adults (OAs) with normal aging and is further reduced in Parkinson's disease (PD), affecting cortical motor and sensorimotor pathways. Levodopa is the prevailing therapy to counter dopamine loss in PD, though not all PD motor signs improve with levodopa. The purpose of this preliminary study was to explore the effects of levodopa on sensorimotor inhibition, gait and quiet standing in OAs and to investigate the relationships between sensorimotor inhibition and both gait and standing balance both OFF- and ON-levodopa. Fifteen OA males completed a gait, balance and sensorimotor assessments before and 1 h after they were given a 100 mg dose of levodopa. Short-latency afferent inhibition quantified sensorimotor inhibition. Wearable sensors characterized gait (two-minute walk) and standing balance (1-min stance). No sensorimotor inhibition, gait, or standing balance measures changed from OFF- to ON-levodopa. When OFF-levodopa, worse inhibition significantly related to increased double stance (r = 0.62; p = 0.01), increased jerkiness of sway (r = 0.57; p = 0.03) and sway area (r = 0.58; p = 0.02). While ON-levodopa, worse inhibition related to increased arm swing range of motion (r = 0.63; p = 0.01) and jerkiness of sway (r = 0.53; p = 0.04). The relationship between SAI and arm swing excursion significantly changed from OFF- to ON-levodopa (z = - 3.05; p = 0.002; 95% confidence interval = - 0.95, - 0.21). Sensorimotor inhibition relationships to both gait and balance may be affected by dopamine in OAs. Cortical restructuring due to the loss of dopamine may be responsible for the heterogeneity of levodopa effect in people with PD and OAs.

Effects of age, sex, frailty and falls on cognitive and motor performance during dual-task walking in older adults

BACKGROUND

Dual-task (DT) walking is of great interest in clinical evaluation to evaluate the risk of falling or cognitive declines in older adults. However, it appears necessary to investigate deeply the confounding factors to better understand their impact on dual-task performance.

OBJECTIVE

To evaluate the effect of age, sex, falls and frailty on cognitive and motor parameters in dual-task walking.

SUBJECTS

66 older participants (mean age = 75.5 ± 6.3; mean height = 165.8 ± 8.4 cm; mean weight = 68.4 ± 14 kgs) were split into groups based on their age, sex, fall and frailty status.

METHODS

Participants performed single-task walking, single-task cognitive (serial subtraction of 3), and dual-task walking (subtraction + walking) for 1 min at their fast pace. Gait speed, step length, step length variability, stance and swing phase time, single and double support, cadence, step time variability and gait speed variability were recorded in single- and dual-task walking and used to calculate the dual-task effect (DTE) as ((DT - ST) / ST) ∗ 100). The cognitive score (DTEcog) was calculated as the number of correct responses minus errors. Generalized linear mixed models (GLMM) were used to compare the effects of falls, frailty, age and sex on gait and cognitive variables.

RESULTS

The interaction frailty*sex and frailty*age were the major effect on the DTEs. Specifically, the DTE was higher in women than men and in the frail group compared to non-frail.

CONCLUSIONS

The present findings provide a better understanding on the confounding factors explaining the behavior in DT that could be used to develop more effective dual-task clinical programs for community-living older adults.

Random walk: Random number generation during backward and forward walking- the role of aging

Deficits in executive function, visuospatial abilities, and cognitive embodiment may impair gait performance. This study aimed to investigate the effect of age on random number generation (RNG) performance during forward and backward locomotion to assess cognitive flexibility and cognitive embodiment during walking. Another aim was to examine the effect of age on the associations of RNG performance during walking with stride time variability (STV), the percentage of double support (DS%), and visuospatial abilities as measured by a spatial orientation test (SOT). Twenty old (age 68.8 ± 5.3, 65% female) and 20 young (age 25.2 ± 2.2, 45% female) adults generated random numbers during backward walking (BW) and forward walking (FW) over-ground and over a treadmill with an internal focus of attention and visual-attentive distraction; six walking conditions in total. To assess cognitive flexibility, sample entropy was calculated for each RNG sequence. The average of the first 5 numbers in each RNG task was calculated to assess the relationship between small/large numbers and movement direction. STV and DS% were recorded using inertial measurement units, and spatial orientation was measured using a computerized test. The older subjects had less flexibility in generating random numbers in three of the six walking conditions. A negative correlation between RNG flexibility and STV was found in older adults during treadmill BW with visual-attentive distraction and forward over-ground walking, whereas no correlations were demonstrated in the young group. The spatial orientation score (a higher value means a worse outcome) correlated positively with RNG flexibility in the older group under all walking conditions, suggesting that older adults with better visuospatial orientation have lower cognitive flexibility, and vice versa. There was no correlation between small/large numbers and direction of motion in either group. The correlation between RNG flexibility and STV may indicate similar executive control of verbal and gait rhythmicity in old adults. Conversely, our results suggest that cognitive flexibility and visuospatial ability may decline differently.

Utilization of Micro-Doppler Radar to Classify Gait Patterns of Young and Elderly Adults: An Approach Using a Long Short-Term Memory Network

To develop a daily monitoring system for early detection of fall risk of elderly people during walking, this study presents a highly accurate micro-Doppler radar (MDR)-based gait classification method for the young and elderly adults. Our method utilizes a time-series of velocity corresponding to leg motion during walking extracted from the MDR spectrogram (time-velocity distribution) in an experimental study involving 300 participants. The extracted time-series was inputted to a long short-term memory recurrent neural network to classify the gaits of young and elderly participant groups. We achieved a classification accuracy of 94.9%, which is significantly higher than that of a previously presented velocity-parameter-based classification method.

Correlates of visuospatial ability among older people in Indonesia

Introduction:

The Indonesian elderly population keeps increasing. Aging is related with degeneration process, one of which is a decrease in cognitive function, including visuospatial ability. This is the first study on the visuospatial ability of Indonesian older people.

Objective:

This research aimed to assess the visuospatial ability and its correlation with sex, age, education, and general cognitive function among older people in Indonesia.

Subjects and Methods:

The research subjects were older people aged ≥60 years with Mini-Mental State Examination (MMSE) score ≥24. The visuospatial ability was assessed using Wechsler Adult Intelligence Scale-Revised (WAIS-R) Block Design Test (BDT). Regression analysis was performed to reveal the correlation of sex, age, education, and global cognitive function with visuospatial ability.

Results:

Sixty older people participated in this research, with an average age of 68.08 ± 6.24, mean MMSE score of 27.43 ± 1.71, and mean WAIS-R BDT score of 27.8 ± 7.27. The female and older individuals tended to have lower scores. Subjects with higher education and global cognitive function had higher WAIS-R BDT scores. Regression analysis showed that age and sex did not have significant effect, but education and global cognitive function had positive effect on visuospatial ability.

Conclusion:

There is a significant correlation between education and global cognitive function with visuospatial ability among older people in Indonesia.

Cortical brain activity in transfemoral or knee-disarticulation prosthesis users performing single- and dual-task walking activities

Introduction

Walking with a prosthesis while performing secondary tasks increases demand on cognitive resources, compromising balance and gait. This study investigated effects of a secondary task on patterns of brain activity and temporospatial gait parameters in individuals using a prosthesis with or without a microprocessor-controlled prosthetic knee(MPK) and controls.

Methods

A cross-sectional study with repeated measures was performed. Twenty-nine individuals with amputations and 16 controls were recruited. Functional near-infrared spectroscopy was used to evaluate changes in oxygenated and de-oxygenated haemoglobin in the prefrontal cortex and temporospatial variables during single-and dual-task walking.

Results

Differences in brain activity were observed within the MPK-group and controls without changes in temporospatial parameters. The Trail-Walking test was associated with highest levels of brain activity in both groups. No differences were observed between single- and dual-task walking in the non-MPK-group (p > 0.05). The Non-MPK and the MPK-group recorded higher levels of brain activity than controls during single-task walking and poorer results on temporospatial variables compared to controls.

Conclusions

For the MPK-group and controls, introduction of a secondary task led to an increase in brain activity. This was not seen in the Non-MPK-group. Significant differences in brain activity were observed in the absence of changes in temporospatial parameters.

The Effects of Systematic Environmental Manipulation on Gait of Older Adults

Quantification of gait changes in response to altered environmental stimuli may allow for improved understanding of the mechanisms that influence gait changes and fall occurrence in older adults. This study explored how systematic manipulation of a single dimension of one’s environment affects spatiotemporal gait parameters. A total of 20 older adult participants walked at a self-selected pace in a constructed research hallway featuring a mobile wall, which allowed manipulation of the hallway width between three conditions: 1.14 m, 1.31 m, and 1.48 m. Spatiotemporal data from participants’ walks were captured using an instrumented GAITRite mat. A repeated measures ANOVA revealed older adults spent significantly more time in double support in the narrowest hallway width compared to the widest, but did not significantly alter other spatiotemporal measures. Small-scale manipulations of a single dimension of the environment led to subtle, yet in some cases significant changes in gait, suggesting that small or even imperceptible environmental changes may contribute to altered gait patterns for older adults.

Walking With Ears: Altered Auditory Feedback Impacts Gait Step Length in Older Adults

Auditory feedback may provide the nervous system with valuable temporal (e. g., footstep sounds) and spatial (e.g., external reference sounds) information that can assist in the control of upright walking. As such, hearing loss may directly contribute to declines in mobility among older adults. Our purpose was to examine the impact of auditory feedback on the control of walking in older adults. Twenty older adults (65-86 years) with no diagnosed hearing loss walked on a treadmill for three sound conditions: Baseline, Ear Plugs, and White Noise. We hypothesized that in response to reduced temporal auditory feedback during the Ear Plugs and White Noise conditions, participants would adapt shorter and faster steps that are traditionally believed to increase mechanical stability. This hypothesis was not supported. Interestingly, we observed increases in step length (p = 0.047) and step time (p = 0.026) during the Ear Plugs condition vs. Baseline. Taking longer steps during the Ear Plugs condition may have increased ground reaction forces, thus allowing participants to sense footsteps via an occlusion effect. As a follow-up, we performed a Pearson's correlation relating the step length increase during the Ear Plugs condition to participants' scores on a clinical walking balance test, the Functional Gait Assessment. We found a moderate negative relationship (rho = -0.44, p = 0.055), indicating that participants with worse balance made the greatest increases in step length during the Ear Plugs condition. This trend suggests that participants may have actively sought auditory feedback with longer steps, sacrificing a more mechanically stable stepping pattern. We also hypothesized that reduced spatial localization feedback during the Ear Plugs and White Noise conditions would decrease control of center of mass (COM) dynamics, resulting in an increase in lateral COM excursion, lateral margin of stability, and maximum Lyapunov exponent. However, we found no main effects of auditory feedback on these metrics (p = 0.580, p = 0.896, and p = 0.056, respectively). Overall, these results suggest that during a steady-state walking task, healthy older adults can maintain walking control without auditory feedback. However, increases in step length observed during the Ear Plugs condition suggest that temporal auditory cues provide locomotor feedback that becomes increasingly valuable as balance deteriorates with age.

Long-term gait measurements in daily life: Results from the Berlin Aging Study II (BASE-II)

Background

Walking ability is an important prerequisite for activity, social participation and independent living. While in most healthy adults, this ability can be assumed as given, limitations in walking ability occur with increasing age. Furthermore, slow walking speed is linked to several chronic conditions and overall morbidity. Measurements of gait parameters can be used as a proxy to detect functional decline and onset of chronic conditions. Up to now, gait characteristics used for this purpose are measured in standardized laboratory settings. There is some evidence, however, that long-term measurements of gait parameters in the living environment have some advantages over short-term laboratory measurements.

Methods

We evaluated cross-sectional data from an accelerometric sensor worn in a subgroup of 554 participants of the Berlin Aging Study II (BASE-II). Data from the two BASE-II age groups (age between 22–36 years and 60–79 years) were used for the current analysis of accelerometric data for a minimum of two days and a maximum of ten days were available. Real world walking speed, number of steps, maximum coherent distance and total distance were derived as average data per day. Linear regression analyses were performed on the different gait parameters in order to identify significant determinants. Additionally, Mann-Whitney-U-tests were performed to detect sex-specific differences.

Results

Age showed to be significantly associated with real world walking speed and with the total distance covered per day, while BMI contributed negatively to the number of walking steps, maximum coherent distance and total distance walked. Additionally, sex was associated with walking steps. However, R²-values for all models were low. Overall, women had significantly more walking steps and a larger coherent distance per day when compared to men. When separated by age group, this difference was significant only in the older participants. Additionally, walking speed was significantly higher in women compared to men in the subgroup of older people.

Conclusions

Age- and sex-specific differences have to be considered when objective gait parameters are measured, e.g. in the context of clinical risk assessment. For this purpose normative data, differentiating for age and sex would have to be established to allow reliable classification of long-term measurements of gait.

The effectiveness of transverse abdominis training on balance, postural sway and core muscle recruitment patterns: a pilot study comparison across age groups

[Purpose] This pilot study aims to determine whether improvements in postural sway, particularly among older adults, can be augmented immediately after training participants to activate and isolate the transverse abdominis (TrA) muscle. [Participants and Methods] Fifty six participants (in three age groups) took part in a single session TrA training intervention. Aspects of postural sway, balance and muscle activation patterns were measured before and after training and compared. [Results] There was significant improvement across four of six postural sway variables for the combined sample of all age groups. Older adults improved more than younger and middle-age participants in two important postural sway variables. No marked differences were evident in static reach distance across all age groups. There were no differences between groups with regard to surface electromyography (sEMG) amplitudes despite the emergence of different activation patterns among age groups. [Conclusion] Immediate effects were induced in postural sway measures after the single session training intervention. By improving neuromuscular control of the TrA and maximizing the efficiency of related proximal core muscles center of pressure (COP) sway velocities decreased during single limb standing (SLS).

The effects of cognitive load and optical flow on antagonist leg muscle coactivation during walking for young and older adults

The purpose of this study was to compare how healthy aging interacts with environments that challenge cognitive load and optical flow to affect antagonist leg muscle coactivation during walking. We measured leg muscle activity in sixteen older adults (70.4 ± 4.2 years) and twelve young adults (23.6 ± 3.9 years) walking on a treadmill at their preferred speed while watching a speed-matched virtual hallway. Cognitive load was challenged using a dual-task to interfere with available attentional resources. Optical flow was challenged using perturbations designed to create a perception of lateral imbalance. We found antagonist coactivation increased with aging, independent of condition. We also found that, compared to unperturbed walking, only in the presence of optical flow perturbations did the older adults increase their antagonist coactivation. Antagonist coactivation in the young adults was not affected by either condition. Our findings provide evidence that antagonist leg muscle coactivation in healthy older adults is more sensitive to walking environments that challenge optical flow than environments that challenge cognitive load. As increased antagonist coactivation may indicate compromised balance, these findings may be relevant in the design of living environments to reduce falls risk.

Combining Russian stimulation with isometric exercise improves strength, balance, and mobility in older people with falls syndrome

One of the main causes of falls in older people is muscle strength loss associated with aging. Russian stimulation can improve muscle strength in healthy individuals, but the effect has never been tested in older individuals with falls syndrome. The aim of this study was to evaluate the usefulness of Russian stimulation plus isometric exercise to improve muscular strength, balance, and mobility in older people with falls syndrome. The recruited participants (older than 60 years, at least one fall in the past year) were evaluated by a physiatrist, who collected clinical data and performed baseline and final evaluations (muscle strength, Berg balance scale, Tinetti mobility test, get up and go test, and 6-min walk test). A physical therapist applied the 10/50/10 protocol for Russian stimulation, stimulating the quadriceps and tibialis anterior muscles separately; simultaneously, the participants performed isometric exercise at a frequency of three sessions per week for 12 weeks. Descriptive statistics, the paired-sample t-test, and the χ-test were performed. The study included 25 participants (96% women, mean age 65.2±5.5 years). After the intervention, there was a significant improvement in the strength of the quadriceps (~30%) and tibialis anterior (~40%) muscles as well as the results of the balance (Tinetti 22%, Berg 10%) and mobility (get up and go 25%, 6-min distance 20%) tests. On the basis of the improvements in the Tinetti and Berg scores, significantly fewer participants were classified as being at increased risk for falls. The muscle strength correlated with several clinical evaluation results, but not with the Tinetti test score. Russian stimulation plus isometric exercise improves strength, balance, and mobility, which may decrease the fall risk.

Differential associations between dual-task walking abilities and usual gait patterns in healthy older adults-Results from the Baltimore Longitudinal Study of Aging

BACKGROUND

It is well established that facing a cognitive challenge while carrying out a motor task interferes with the motor task performance, and in general the ability of handling a dual-task declines progressively with aging. However, the reasons for this decline have not been fully elucidated. Understanding the association between usual-walking gait patterns and dual-task walking performance may provide new insights into the mechanisms that lead to gait deterioration in normal aging and its link to motor and cognitive function.

RESEARCH QUESTION

Our aim was to assess usual gait parameters in kinematics and kinetics to understand how these parameters are related with a specific task in dual-task walking.

METHODS

We hypothesized that difficulty in dual-task walking would be associated with gait deteriorations as reflected in range of motion and mechanical work expenditure. We tested this hypothesis by quantifying the gait of 383 participants in the Baltimore Longitudinal Study of Aging (68% of whom successfully completed the dual-task walk, 21% failed the motor task, and 11% failed the cognitive task).

RESULTS

Compared to successful performers, participants who failed the single motor task had slower gait speed, shorter stride length, higher cadence, and lower range of motion in the knee and ankle joints (p < 0.05, for all), while the participants who failed the cognitive task while walking had longer double support time (p = 0.003), and greater knee absorptive mechanical work (p = 0. 001) and lower ankle generative mechanical work (p < 0. 001).

SIGNIFICANCE

These results suggest that dual-task walking may be useful for monitoring subtle and diverse gait deteriorations in aging and possibly for designing interventions for maintaining and regaining proper gait patterns in older adults.

Adaptation and post-adaptation effects of haptic forces on locomotion in healthy young adults

BACKGROUND

Developing rehabilitation strategies to improve functional walking and postural control in patients is a priority for rehabilitation clinicians and researchers alike. One possible strategy is the use of sensory modalities to elicit adaptive locomotor gait patterns. This study aimed to explore to what extent haptic inputs, in the form of forward-leading tensile forces delivered to the hand, compared to no force, may lead to adaptation and post-adaptation effects on gait parameters, during and after the haptic exposure, respectively.

METHODS

Thirteen healthy young individuals were recruited for this study. We developed an innovative system combining virtual reality and haptic tensile forces in the direction of locomotion to simulate walking with a dog. A robotic arm generated forces via an adapted leash to the participant's hand while they walked on a self-paced treadmill immersed in a virtual environment with scene progression synchronized to the treadmill.

RESULTS

All participants showed significant increases in instantaneous gait velocity and stride length, with accompanying decreases in double-limb support time (p < 0.05) when walking with a haptic tensile force of either 10 or 20 N, relative to pre-force epoch levels, indicating an adaptation effect. When the 10 or 20 N force was removed, gait measures generally remained changed relative to baseline pre-force levels (p < 0.05), providing evidence of a post-adaptation effect.

CONCLUSIONS

Changes in spatiotemporal outcomes provide evidence that both adaptation and post-adaptation effects were present in response to the application and removal of a haptic force. Future studies will investigate whether similar changes in elderly and post-stroke populations can be actualized during steady-state walking.

Impact of cognitive fatigue on gait and sway among older adults: A literature review

Cognitive fatigue is an alteration in central nervous system (CNS) processing due to prolonged performance of mentally demanding tasks. Decreased gait speed and increased stride length variability have been noted in cognitively fatigued older adults (≥ 65 years). Further, cognitive fatigue may weaken the visual, vestibular, and proprioceptive systems of the CNS, contributing to increased postural sway. Detriments in gait and sway caused by cognitive fatigue could increase fall risk. The objective of this literature review was to evaluate the impact of cognitive fatigue on changes in gait and postural sway and its role in fall risk.

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Cognitive fatigue may cause gait disturbances in older adults (≥ 65 years).

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Cognitive fatigue may increase postural sway in older adults.

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Cognitive fatigue may be considered a fall risk for older adults.

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Interventions to attenuate cognitive fatigue should be further explored.

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Studies should explore the role of cognitive fatigue in fall risk.

Medidas temporoespaciais indicativas de quedas em mulheres saudáveis entre 50 e 70 anos avaliadas pela análise tridimensional da marcha

RESUMO Objetivou-se comparar e correlacionar medidas temporoespaciais da marcha indicativas de quedas. Participaram do estudo 35 mulheres saudáveis, sem histórico de quedas no ano da avaliação. A análise computadorizada tridimensional da marcha forneceu cinco medidas temporoespaciais de cada participante, dos membros inferiores direito (D) e esquerdo (E). A análise inferencial abordou dois grupos de mulheres: jovens (20 40 anos) e adultas-idosas (50-70 anos). Houve diferença estatística significativa entre os grupos para comprimento da passada D (p=0,003) e E (p=0,002); passo D (p=0,008) e E (p=0,001); tempo de apoio E (p=0,008); tempo de passo D (p=0,049); tempo de apoio duplo E (p=0,003); largura da base E (p=0,005); resposta à carga E (p=0,001); pré-balanço D (p=0,001) e E (p=0,001) e para algumas medidas em percentil do ciclo de marcha: apoio E (p=0,001); balanço E (p=0,001); apoio simples E (p=0,025); resposta à carga E (p=0,00); pré-balanço E (p=0,001) e pré-balanço D (p=0,014). A regressão linear indicou que a variação da idade modificou em média 18% as medidas de comprimento do passo e da passada e em 20% a velocidade da marcha. Com o avanço da idade, as medidas funcionais diminuíram; e, consequentemente, as medidas de estabilidade, como duração dos períodos de apoio, apoio duplo e pré-balanço, aumentaram. Essas modificações indicam risco de queda na faixa etária de 50 a 70 anos. Algumas medidas de marcha podem apresentar alteração em uma faixa etária ainda considerada de baixo risco.

Improved motor and cognitive performance with sodium nitrite supplementation is related to small metabolite signatures: a pilot trial in middle-aged and older adults

Advancing age is associated with reductions in nitric oxide bioavailability and changes in metabolic activity, which are implicated in declines in motor and cognitive function. In preclinical models, sodium nitrite supplementation (SN) increases plasma nitrite and improves motor function, whereas other nitric oxide-boosting agents improve cognitive function. This pilot study was designed to translate these findings to middle-aged and older (MA/O) humans to provide proof-of-concept support for larger trials. SN (10 weeks, 80 or 160 mg/day capsules, TheraVasc, Inc.) acutely and chronically increased plasma nitrite and improved performance on measures of motor and cognitive outcomes (all p<0.05 or better) in healthy MA/O adults (62 ± 7 years). Untargeted metabolomics analysis revealed that SN significantly altered 33 (160 mg/day) to 45 (80 mg/day) different metabolites, 13 of which were related to changes in functional outcomes; baseline concentrations of 99 different metabolites predicted functional improvements with SN. This pilot study provides the first evidence that SN improves aspects of motor and cognitive function in healthy MA/O adults, and that these improvements are associated with, and predicted by, the plasma metabolome. Our findings provide the necessary support for larger clinical trials on this promising pharmacological strategy for preserving physiological function with aging.

Relationship between frequent knee pain, obesity, and gait speed in older adults: data from the Osteoarthritis Initiative

Background

Knee pain (KP) causes gait difficulties in older adults and is associated with slow gait speed (GS). Obesity has negative effects on health. GS is an important indicator of health, well-being, and mean life span in older adults and is a strong predictor of future disability and mortality. The relationship between frequent KP, obesity, and GS in older adults remains unclear. Therefore, the present study aimed at examining the relationship between baseline frequent KP and obesity status on GS over time. We hypothesized that frequent KP, obesity, or both would be associated with decreased GS over time.

Methods

The data from the Osteoarthritis Initiative were used for this 6-year longitudinal cohort study. We studied 3,118 adults aged between 45 years and 79 years. We grouped the participants into the following four categories according to KP frequency and obesity status at baseline: 1) no KP and nonobese, 2) frequent KP and nonobese, 3) no KP and obese, and 4) frequent KP and obese. GS measurements were based on a 20 m walking test timed using a stopwatch; testing was performed at baseline and over a 6-year follow-up period. Walk pace (m/sec) was calculated as the average pace over two trials conducted at clinic visits. General linear mixed models were used to examine the relationships between frequent KP, obesity, and GS.

Results

After adjusting for all covariates, at baseline, all the nonobese group with frequent KP (β=−0.06, 95% confidence interval [CI]: −0.07 to −0.04), the obese group with no KP (β=−0.07, 95% CI: −0.1 to −0.04), and the obese group with frequent KP (β=−0.08, 95% CI: −0.1 to −0.05) exhibited decreased GS compared with the nonobese and no KP group. However, the associations between frequent KP, obesity, and GS over time were not statistically significant.

Conclusion

Frequent KP alone, obesity alone, and the combination of frequent KP and obesity were all associated with decreased GS in older adults. These associations did not change in any of the groups longitudinally; as such, the slopes corresponding to the data remained unchanged.

Analysis of Choice Stepping with Visual Interference Can Detect Prolonged Postural Preparation in Older Adults with Mild Cognitive Impairment at High Risk of Falling

BACKGROUND/AIMS

We aimed to clarify postural control deficits in older adults with mild cognitive impairment (MCI) at high risk of falling by addressing the inhibitory process.

METHODS

This study involved 376 community-dwelling older adults with MCI. Participants were instructed to execute forward stepping on the side indicated by the central arrow while ignoring the 2 flanking arrows on each side (→→→→→, congruent, or →→←→→, incongruent). Initial weight transfer direction errors [anticipatory postural adjustment (APA) errors], step execution times, and divided phases (reaction, APA, and swing phases) were measured from vertical force data. Participants were categorized as fallers (n = 37) and non-fallers (n = 339) based on fall experiences in the last 12 months.

RESULTS

There were no differences in the step execution times, swing phases, step error rates, and APA error rates between groups, but fallers had a significantly longer APA phase relative to non-fallers in trials of the incongruent condition with APA errors (p = 0.005). Fallers also had a longer reaction phase in trials with the correct APA, regardless of the condition (p = 0.01).

CONCLUSION

Analyses of choice stepping with visual interference can detect prolonged postural preparation as a specific falling-associated deficit in older adults with MCI.

Correlation between the Quality of Attention and Cognitive Competence with Motor Action in Stroke Patients

It is considered that cognitive function and attention could affect walking, motion control, and proper conduct during the walk. To determine whether there is a difference in the quality of attention and cognitive ability in stroke patients and patients without neurological damage of similar age and education and to determine whether the connection of attention and cognition affects motor skills, the sample consisted of 50 stroke patients tested with hemiparesis, involved in the process of rehabilitation, and 50 persons, randomly chosen, without neurological damage. The survey used the following tests: Trail Making (TMT A B) test for assessing the flexibility of attention; Mini-Mental State Examination (MMSE) for cognitive status; Functional Ambulation Category (FAC) test to assess the functional status and parameters of walk: speed, frequency, and length of stride; STEP test for assessing the precision of movement and balance. With stroke patients, relationship between age and performance on the MMSE test was marginally significant. The ratio of performance to TMT A B test and years does not indicate statistical significance, while statistical significance between the MMSE test performance and education exists. In stroke patients, performance on MMSE test is correlated with the frequency and length of stride walk. The quality of cognitive function and attention is associated with motor skills but differs in stroke patients and people without neurological damage of similar age. The significance of this correlation can supplement research in neurorehabilitation, improve the quality of medical rehabilitation, and contribute to efficient recovery of these patients.