Prefrontal cortical activity during uneven terrain walking in younger and older adults.

Introduction: Walking in complex environments increases the cognitive demand of locomotor control; however, our understanding of the neural mechanisms contributing to walking on uneven terrain is limited. We used a novel method for altering terrain unevenness on a treadmill to investigate the association between terrain unevenness and cortical activity in the prefrontal cortex, a region known to be involved in various cognitive functions. Methods: Prefrontal cortical activity was measured with functional near infrared spectroscopy while participants walked on a novel custom-made terrain treadmill surface across four different terrains: flat, low, medium, and high levels of unevenness. The assessments were conducted in younger adults, older adults with better mobility function and older adults with worse mobility function. Mobility function was assessed using the Short Physical Performance Battery. The primary hypothesis was that increasing the unevenness of the terrain would result in greater prefrontal cortical activation in all groups. Secondary hypotheses were that heightened prefrontal cortical activation would be observed in the older groups relative to the younger group, and that prefrontal cortical activation would plateau at higher levels of terrain unevenness for the older adults with worse mobility function, as predicted by the Compensation Related Utilization of Neural Circuits Hypothesis. Results: The results revealed a significant main effect of terrain, indicating a significant increase in prefrontal cortical activation with increasing terrain unevenness during walking in all groups. A significant main effect of group revealed that prefrontal cortical activation was higher in older adults with better mobility function compared to younger adults and older adults with worse mobility function in all pooled terrains, but there was no significant difference in prefrontal cortical activation between older adults with worse mobility function and younger adults. Contrary to our hypothesis, the older group with better mobility function displayed a sustained increase in activation but the other groups did not, suggestive of neural compensation. Additional findings were that task-related increases in prefrontal cortical activation during walking were lateralized to the right hemisphere in older adults with better mobility function but were bilateral in older adults with worse mobility function and younger adults. Discussion: These findings support that compared to walking on a flat surface, walking on uneven terrain surfaces increases demand on cognitive control resources as measured by prefrontal cortical activation.

Exploratory and confirmatory factor analyses identify three structural dimensions for measuring physical function in community-dwelling older adults.

Background: Physical function is a strong indicator of biological age and quality of life among older adults. However, the results from studies exploring the structural dimensions of physical function are inconsistent, and the measures assessed vary greatly, leading to a lack of comparability among them. This study aimed to construct a model to identify structural dimensions that are suitable and best assess physical function among community-dwelling adults 60-74 years of age in China. Method: This study was conducted in 11 communities in Shanghai, China, from May to July 2021. A total of 381 adults 60-74 years of age were included in the study. Measured physical function data were used in factor analyses. Data collected from individuals were randomly assigned to either exploratory factor analysis (EFA) (n = 190) or confirmatory factor analysis (CFA) (n = 191). The statistical software used in the study was SPSS for EFA and AMOS for CFA. To test the properties of the structural dimension model of physical function, various fit indices, convergent validity, and discriminant validity were calculated. Results: The EFA results derived seven indicators in three factors, with 58.548% of the total variance explained. The three factors were mobility function (three indicators), which explained 26.380% of the variance, handgrip strength and pulmonary function (two indicators), which explained 19.117% of the variance, and muscle strength (two indicators) which explained 13.050% of the variance. The CFA indicated that this model had an acceptable fit (χ2/df ratio, 2.102; GFI, 0.967; IFI, 0.960; CFI, 0.959; and RMSEA, 0.076), and the criteria for convergent validity and discriminability were also met by the model. Conclusion: The constructed structural dimension model of physical function appeared to be a suitable and reliable tool to measure physical function in community-dwelling adults aged 60-74 years in China. The structural dimension indicators identified by this model may help sports medicine experts and healthcare providers offer more targeted interventions for older adults to reverse or slow the decline of physical function and to offer actionable targets for healthy aging in this population.

Dynamic coarse-graining of polymer systems using mobility functions.

We propose a dynamic coarse-graining (CG) scheme for mapping heterogeneous polymer fluids onto extremely CG models in a dynamically consistent manner. The idea is to use as target function for the mapping a wave-vector dependent mobility function derived from the single-chain dynamic structure factor, which is calculated in the microscopic reference system. In previous work, we have shown that dynamic density functional calculations based on this mobility function can accurately reproduce the order/disorder kinetics in polymer melts, thus it is a suitable starting point for dynamic mapping. To enable the mapping over a range of relevant wave vectors, we propose to modify the CG dynamics by introducing internal friction parameters that slow down the CG monomer dynamics on local scales, without affecting the static equilibrium structure of the system. We illustrate and discuss the method using the example of infinitely long linear Rouse polymers mapped onto ultrashort CG chains. We show that our method can be used to construct dynamically consistent CG models for homopolymers with CG chain lengthN= 4, whereas for copolymers, longer CG chain lengths are necessary.

Gait and Balance Disorder in Patients with Transient Ischemic Attack or Minor Stroke.

PURPOSE: Transient ischemic attack (TIA) and minor stroke had a high recurrence rate, resulting in potential neurological impairment. Only a few previous studies focused on gait and balance disorder in TIA and minor stroke. This study aimed to explore the relationship between gait and balance disorder and TIA/minor stroke. PATIENTS AND METHODS: Eighty-two patients with TIA/minor stroke and fifty-two healthy control participants were recruited. The gait and balance function of the two groups was tested with six measurements (Four Square Step, Tandem, Functional Reach, Gait and Pivot Turn, Timed "Up and Go", and Single Leg Balance tests). The associations between these measures and TIA/minor stroke were determined through linear and logistic regression analyses. RESULTS: There were no significant group differences in age, gender, body mass index, vision, and cognitive function. People with TIA/minor stroke had poorer performance in all six gait and balance measures (all p<0.05). Logistic regression analysis showed TIA/minor stroke was strongly associated with gait and balance disorder (Four Square Step Test [OR, 24.07; 95% CI 5.90-98.13; p<0.001], Tandem Test [OR, 5.50; 95% CI 1.64-18.40; p=0.006], Functional Reach Test [OR, 4.25; 95% CI 1.04-17.33; p=0.044], Gait and Pivot Turn Test [OR, 3.78; 95% CI 1.22-11.31; p=0.021], Timed"Up and Go"Test [OR, 15.79; 95% CI 2.32-107.48; p=0.005], and Single Leg Balance Test [OR, 8.96; 95% CI 2.34-34.01; p=0.001]). TIA/minor stroke patients with older age, cognitive dysfunction, high K-CRP level, and severe atherosclerosis in lower limbs were more likely to have gait and balance disorder. CONCLUSION: Our findings highlight the significant relationship between gait and balance disorder and TIA/minor stroke. It seems that people with TIA/minor stroke had a higher possibility to get gait and balance disorder. Gait and balance disorder following a minor stroke or TIA may be attributed to cognitive function in these patients.

Effects of rural community-based integrated exercise and health education programs on the mobility function of older adults with knee osteoarthritis.

AIM: To examine the effects of a rural community-based program integrating health education and self-directed home-based resistance training on the mobility function of older women with knee osteoarthritis (OA). METHODS: Participants were assigned to the control (CON) or intervention (INT) group. Participants completed a mobility function assessment and questionnaire evaluation. The CON group received only the health education program and the INT group also participated in resistance training for 5 months. Primary outcomes were mobility function measured using a timed chair stand (TCS), timed up & go (TUG), gait speed (GS), and knee extensor strength (KES). We evaluated body composition and questionnaire results (WOMAC score, SARC-F scale, and SOF index) as secondary outcomes. RESULTS: There were significant differences in the interactions of group-by-time effects for TCS (p < 0.001), TUG (p = 0.006), GS (p = 0.020), and knee strength (p = 0.010). In the CON group, TCS (p = 0.003) and TUG (p = 0.005) increased compared with baseline, while in the INT group, TCS decreased significantly (p < 0.001) and TUG tended to decrease after the intervention. The INT group showed improvement in GS (p < 0.001) and KES (p = 0.003) after the intervention. By contrast, the CON group showed decreasing GS (p = 0.021) and KES (p = 0.011) compared with baseline. The SARC-F scale differed significantly in the interaction of group-by-time effects (p = 0.030), while the body composition, SOF index, and WOMAC score did not differ. CONCLUSION: These results suggest that an integrated intervention program combining self-directed home-based resistance training with health education effectively improves the mobility function of older adults with knee OA dwelling in rural areas.

The effects of dietary licorice flavonoid oil supplementation on body balance control in healthy middle-aged and older Japanese women undergoing a physical exercise intervention: a randomized, double-blind, placebo-controlled trial.

AIMS: In this study, the effects of licorice flavonoid oil (LFO) supplementation on mobility functions were evaluated in middle-aged and older women who underwent daily physical exercise. METHODS: The 73 women aged 59-85 years (71.2 ± 5.2 years) were randomly assigned to the LFO group (n = 37) or the placebo group (n = 36). For 16 weeks, the LFO group consumed a daily capsule containing 300 mg of LFO, while the placebo group consumed a placebo capsule. All participants were instructed to complete a strength training program during the 16 weeks and to increase their daily step count by 1000. 10-m walking speed (with/no obstruction), one-leg standing time with eyes open, handgrip strength, isometric knee extension strength, and body composition were evaluated at baseline and every eight weeks. RESULTS: In the 10-m walking speeds (with/no obstruction), LFO supplementation did not show significant improvements. One-leg standing time was significantly prolonged with LFO intake (LFO: baseline 73.9 s vs 16 weeks 93.5, placebo: baseline 82.8 vs 16 weeks 87.1, p = 0.03). In addition, a significant decrease in BMI and body fat percentage with LFO was found (p = 0.01, p = 0.03, respectively). DISCUSSION: Since a lower BMI corresponds to a lighter physical load on the lower limb, in addition, since LFO might improve skeletal muscle function by antioxidant activity, participants could stand longer and body balance control was improved. CONCLUSION: LFO supplementation improved body balance control and may contribute to fall prevention in healthy middle-aged and older women having daily physical exercise. TRIAL REGISTRATION: UMIN Clinical Trial Registry No. 000029712.

Effects of an individually targeted multicomponent counseling and home-based rehabilitation program on physical activity and mobility in community-dwelling older people after discharge from hospital: a randomized controlled trial.

OBJECTIVES: The aim of this study is to evaluate the effects of multicomponent rehabilitation on physical activity, sedentary behavior, and mobility in older people recently discharged from hospital. DESIGN: Randomized controlled trial. SETTING: Home and community. PARTICIPANTS: Community-dwelling people aged ⩾60 years recovering from a lower limb or back musculoskeletal injury, surgery, or disorder were recruited from local health center hospitals and randomly assigned into an intervention (n = 59) or a control (standard care, n = 58) group. INTERVENTION: The six-month intervention consisted of a motivational interview, goal attainment process, guidance for safe walking, a progressive home exercise program, physical activity counseling, and standard care. MEASUREMENTS: Physical activity and sedentary time were assessed using an accelerometer and a single question. Mobility was evaluated with the Short Physical Performance Battery, self-reported use of a walking aid, and ability to negotiate stairs and walk outdoors. Intervention effects were analyzed with generalized estimating equations. RESULTS: Daily physical activity was 127 ± 78 minutes/day and 121 ± 70 at baseline and 167 ± 81 and 164 ± 72 at six months in the intervention and control group, respectively; mean difference of 3.4 minutes (95% confidence interval (CI) = -20.3 to 27.1). In addition, no significant between-group differences were shown in physical performance. CONCLUSION: The rehabilitation program was not superior to standard care for increasing physical activity or improving physical performance. Mobility-limited older people who had recently returned home from hospital would have needed a longer and more frequently monitored comprehensive geriatric intervention.

Effect of exergames on physical outcomes in frail elderly: a systematic review.

AIM: The aim of this systematic review was to understand the exergames that can be applied to the pre-frail and frail elderly people, to evaluate whether these games have a positive impact on physical outcomes in pre-frail and frail older adults, and to explore user's subjective feelings and compliance. METHODS: PubMed, EMBASE, CINAHL, Web of Science, and the Cochrane Library were searched until January 15, 2019. Only randomized controlled trials published in English for human beings were eligible. The review included studies which examined the effects of exergames on physical outcomes, feasibility and/or subjective feelings of pre-frail and frail older adults. Two researchers assessed the risk bias of all articles independently using the Cochrane collaboration's tool for assessing risk of bias. RESULTS: Seven randomized controlled trials with 243 pre-frail and frail older adults met inclusion criteria and were included in this review. Results of the studies were heterogeneous. Physical outcomes (included muscle strength, balance ability, mobility function, gait and falls), subjective feeling outcomes, feasibility, attendance and some other functional outcomes were reported. CONCLUSION: Exergames improved balance and mobility function of frail elderly, and it showed a tendency to increase muscle strength when combined with resistance training. As far as the limited evidence was concerned, exergames were feasible and generally accepted by participants.

Physical Function Does Not Predict Care Assessment Need Score in Older Veterans.

Objective: The Veterans Health Administration's Care Assessment Need (CAN) score is a statistical model, aimed to predict high-risk patients. We were interested in determining if a relationship existed between physical function and CAN scores. Method: Seventy-four older (71 ± 1 years) male Veterans underwent assessment of CAN score and subjective (Short Form-36 [SF-36]) and objective (self-selected walking speed, four square step test, short physical performance battery) assessment of physical function. Results: Approximately 25% of participants self-reported limitations performing lower intensity activities, while 70% to 90% reported limitations with more strenuous activities. When compared with cut points indicative of functional limitations, 35% to 65% of participants had limitations for each of the objective measures. Any measure of subjective or objective physical function did not predict CAN score. Conclusion: These data indicate that the addition of a physical function assessment may complement the CAN score in the identification of high-risk patients.

Clinical relevance of the modified physical performance test versus the short physical performance battery for detecting mobility impairments in older men with peripheral arterial disease.

PURPOSE: The study is to compare the Modified Physical Performance Test (MPPT) and Short Physical Performance Battery (SPPB) as metrics of mobility and function in older men with peripheral arterial disease (PAD). MATERIALS AND METHODS: A total of 51 men (55-87 years) with PAD underwent functional testing including the SPPB, MPPT, Walking Impairment Questionnaire (WIQ), stair ascent, and 6-min walk distance. Individuals were grouped according to SPPB and MPPT scores as not limited on either, limited only on the MPPT, or limited on both. RESULTS: The MPPT identified a higher proportion of patients as being functionally limited than the SPPB (p < 0.001). Men identified as limited only by the MPPT, and not the SPPB, were subsequently confirmed to have lower function on all measures compared to those not identified as limited by either the SPPB or the MPPT (p < 0.02). CONCLUSIONS: These findings suggest the MPPT is an appropriate measure to identify early declines in men with PAD and may identify global disability better than SPPB. Implications for rehabilitation Individuals with peripheral arterial disease have low activity levels and are at risk for a loss of independence and global disability. Early detection of decline in mobility and global function would allow for interventions before large changes in ambulatory ability or a loss of functional independence occur. This study shows the Modified Physical Performance Test may be an appropriate test to identify early decline in function in men with peripheral arterial disease.

Functional visual fields: a cross-sectional UK study to determine which visual field paradigms best reflect difficulty with mobility function.

OBJECTIVES: To develop an appropriate method of assessing visual field (VF) loss which reflects its functional consequences, this study aims to determine which method(s) of assessing VF best reflect mobility difficulty. SETTING: This cross-sectional observational study took place within a single primary care setting. Participants attended a single session at a University Eye Clinic, Cambridge, UK, with data collected by a single researcher (HS), a qualified optometrist. PARTICIPANTS: 50 adult participants with peripheral field impairment were recruited for this study. Individuals with conditions not primarily affecting peripheral visual function, such as macular degeneration, were excluded from the study. PRIMARY AND SECONDARY OUTCOME MEASURES: Participants undertook three custom and one standard binocular VF tests assessing VF to 60°, and also integrated monocular threshold 24-2 visual fields (IVF). Primary VF outcomes were average mean threshold, percentage of stimuli seen and VF area. VF outcomes were compared with self-reported mobility function assessed with the Independent Mobility Questionnaire, and time taken and patient acceptability were also considered. Receiver operating characteristic (ROC) curves determined which tests best predicted difficulty with mobility tasks. RESULTS: Greater VF loss was associated with greater self-reported mobility difficulty with all field paradigms (R2 0.38-0.48, all P<0.001). All four binocular tests were better than the IVF at predicting difficulty with at least three mobility tasks in ROC analysis. Mean duration of the tests ranged from 1 min 26 s (±9 s) for kinetic assessment to 9 min 23 s (±24 s) for IVF. CONCLUSIONS: The binocular VF tests extending to 60° eccentricity all relate similarly to self-reported mobility function, and slightly better than integrated monocular VFs. A kinetic assessment of VF area is quicker than and as effective at predicting mobility function as static threshold assessment.

The Effects of Chronic Medical Conditions and Obesity on Self-Reported Disability in Older Mexican Americans.

We investigated the effect of chronic medical conditions including obesity on self-reported disability and mobility in Mexican Americans aged 75 or over using data from the Hispanic Established Population for the Epidemiological Study of the Elderly (Hispanic EPESE) Wave 5 (2004-2005). Disability was assessed with a modified version of the Katz activities of daily living (ADL) scale and mobility was assessed with the Rosow Breslau scale of gross mobility function. The percentage of participants needing assistance with ADLs were as follows: 26.7% for transferring from a bed to chair, 26.6% for walking across a small room, 17.9% for dressing, 16.3% for using a toilet, 14.3% for grooming, and 8.2% for eating. Fifty percent reported limitation in the ability to walk ½ a mile and walking up and down stairs. Multivariate logistic regression analysis after controlling for all covariates showed that arthritis, diabetes, stroke, and obesity were significantly associated with any ADL limitation, walking up and down stairs, and walking 1/2 mile. Prevention of obesity and chronic medical conditions will help increase functional independence in this population.

Functional visual fields: relationship of visual field areas to self-reported function.

PURPOSE: The aim of this study is to relate areas of the visual field to functional difficulties to inform the development of a binocular visual field assessment that can reflect the functional consequences of visual field loss. METHODS: Fifty-two participants with peripheral visual field loss undertook binocular assessment of visual fields using the 30-2 and 60-4 SITA Fast programs on the Humphrey Field Analyser, and mean thresholds were derived. Binocular visual acuity, contrast sensitivity and near reading performance were also determined. Self-reported overall and mobility function were assessed using the Dutch ICF Activity Inventory. RESULTS: Greater visual field loss (0-60°) was associated with worse self-reported function both overall (R2 = 0.50; p < 0.0001), and for mobility (R2 = 0.64; p < 0.0001). Central (0-30°) and peripheral (30-60°) visual field areas were similarly related to mobility function (R2 = 0.61, p < 0.0001 and R2 = 0.63, p < 0.0001 respectively), although the peripheral (30-60°) visual field was the best predictor of mobility self-reported function in multiple regression analyses. Superior and inferior visual field areas related similarly to mobility function (R2 = 0.56, p < 0.0001 and R2 = 0.67, p < 0.0001 respectively). The inferior field was found to be the best predictor of mobility function in multiple regression analysis. CONCLUSION: Mean threshold of the binocular visual field to 60° eccentricity is a good predictor of self-reported function overall, and particularly of mobility function. Both the central (0-30°) and peripheral (30-60°) mean threshold are good predictors of self-reported function, but the peripheral (30-0°) field is a slightly better predictor of mobility function, and should not be ignored when considering functional consequences of field loss. The inferior visual field is a slightly stronger predictor of perceived overall and mobility function than the superior field.