Usual Pace Research Articles

Catechol-O-methyltransferase (COMT) polymorphism predicts rapid gait speed changes in healthy older adults.

Adapting one's gait speed to external circumstances is critical for safe ambulation. Dopamine (DA), critical for adapting to increased task demands, predicts usual gait speed and may exert a greater role in complex tasks like rapid gait speed. We hypothesized that a genotypic proxy indicator of greater prefrontal DA signaling would predict significantly faster rapid gait. Longitudinal cohort study over 8 years. Community-dwelling adults with no baseline mobility disability. N=2353 participants from the Health ABC Study. Repeated measures of walking speed (meters/sec) were obtained in response to: "walk as fast as possible… (rapid gait) or "walk at your usual pace (usual gait)." Catechol-O-methyltransferase (COMT) val158met polymorphism indicated DA signaling (val/val=higher metabolism, lower DA signaling; met/met=lower metabolism, higher DA signaling). Participants declined in rapid gait from 1.55 (SD=0.33) to 1.35 m/s (SD=0.34). Across the full follow-up period, the met/met genotype was associated with significantly greater rapid gait slowing. In mixed effect models, between-group differences were independent of covariates, and remained similar after adjustment for sensorimotor function, cognition, depressive symptoms, and energy. Follow-up analyses indicated the met/met genotype had a significantly faster rapid gait speed compared to the val/val genotype for the first 3 years (p < 0.01) but not years 4-8 (p > 0.05). Greater prefrontal DA measured with COMT polymorphism may facilitate short-term adaptation to rapid walking demands that are lost over time. Studies should examine whether these effects are long-term and the underlying mechanistic pathways.

Measuring Outdoor Walking Capacities Using Global Positioning System in People with Multiple Sclerosis: Clinical and Methodological Insights from an Exploratory Study.

We aimed at showing how Global Positioning System (GPS) along with a previously validated speed processing methodology could be used to measure outdoor walking capacities in people with multiple sclerosis (MS). We also deal with methodological issues that may occur when conducting such measurements, and explore to what extent GPS-measured outdoor walking capacities (maximal walking distance [MWDGPS] and usual walking speed) could be related to traditional functional outcomes (6-min total walking distance) in people with MS. Eighteen people with MS, with an Expanded Disability Status Scale score ≤6, completed a 6-min walking test and an outdoor walking session (60 min maximum) at usual pace during which participants were wearing a DG100 GPS receiver and could perform several walking bouts. Among the 12 participants with valid data (i.e., who correctly completed the outdoor session with no spurious GPS signals that could prevent the detection of the occurrence of a walking/stopping bout), the median (90% confidence interval, CI) outdoor walking speed was 2.52 km/h (2.17; 2.93). Ten participants (83% (56; 97)) had ≥1 stop during the session. Among these participants, the median of MWDGPS was 410 m (226; 1350), and 40% (15; 70) did not reach their MWDGPS during the first walking bout. Spearman correlations of MWDGPS and walking speed with 6-min total walking distance were, respectively, 0.19 (−0.41; 0.95) and 0.66 (0.30; 1.00). Further work is required to provide guidance about GPS assessment in people with MS.

The association between white matter hyperintensity volume and gait performance under single and dual task conditions in older people with dementia: A cross-sectional study

Background: Understanding the relationship between white matter hyperintensities (WMHs) and gait may assist in understanding the central control of gait and determining treatment modalities. These relationships are yet to be realized in older people with dementia. Objective: To examine the association between WMH volume and gait under single-task and dual task (DT) conditions in people with dementia. Methods: Twenty-eight community-dwelling older people with dementia (median age=83 years; [IQR=77–86]; 36% female) had timed gait speed assessed at usual pace. Gait (speed, stride length, cadence) was assessed using the GAITRite® mat under three conditions (n = 18/28): a) single-task, b) functional DT: carrying a glass of water and c) cognitive DT: counting backwards from 30. WMH volumes were quantified using a fully automated segmentation toolbox. Results: Total, temporal and parietal WMH volumes were negatively correlated with timed and functional DT gait speed, and with stride length under single-task, functional DT and cognitive DT conditions. Frontal WMH volumes were negatively correlated with timed gait speed and stride length under single-task and functional DT conditions. Participants with higher total WMH burden had significantly slower timed and functional DT gait speed and reduced stride length under single-task, functional DT and cognitive DT conditions compared to participants with lower WMH burden. Conclusions: WMH volume was associated with slower gait speed and reduced stride length, but not cadence, under single-task and DT conditions in people with dementia. Further research is needed to confirm these findings and determine whether vascular risk management can improve gait in older people with dementia.

Detection of Motor Dysfunction With Wearable Sensors in Patients With Idiopathic Rapid Eye Movement Disorder.

Patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) are at high risk for conversion to synucleinopathy and Parkinson disease (PD). This can potentially be monitored by measuring gait characteristics of iRBD patients, although quantitative data are scarce and previous studies have reported inconsistent findings. This study investigated subclinical gait changes in polysomnography-proven iRBD patients compared to healthy controls (HCs) during 3 different walking conditions using wearable motor sensors in order to determine whether gait changes can be detected in iRBD patients that could reflect early symptoms of movement disorder. A total 31 iRBD patients and 20 HCs were asked to walk in a 10-m corridor at their usual pace, their fastest pace, and a normal pace while performing an arithmetic operation (dual-task condition) for 1 min each while using a wearable gait analysis system. General gait measurements including stride length, stride velocity, stride time, gait length asymmetry, and gait variability did not differ between iRBD patients and HCs; however, the patients showed decreases in range of motion (P = 0.004) and peak angular velocity of the trunk (P = 0.001) that were significant in all 3 walking conditions. iRBD patients also had a longer step time before turning compared to HCs (P = 0.035), and the difference between groups remained significant after adjusting for age, sex, and height. The decreased trunk motion while walking and increased step time before turning observed in iRBD may be early manifestations of body rigidity and freezing of gait and are possible prodromal symptoms of PD.

What Is an Important Difference in Gait Speed in Adults With Knee Osteoarthritis?

Little is known regarding what difference in functional performance measures is significant in individuals with chronic medical disease. Our objective was to examine the important differences in gait speed in adults with radiographic knee osteoarthritis. Functional performance was measured by gait speed using 20-meter and 400-meter walk tests performed at a self-selected usual pace among adults with radiographic knee osteoarthritis participating in the Osteoarthritis Initiative at baseline and 2 years later. Both distribution-based methods and anchor-based methods were used to calculate the important differences in gait speed. Anchor-based methods used the chair stand rate and self-reported function to estimate gait speed differences related to physical function. We included 2,527 participants with radiographic knee osteoarthritis. Distribution-based important difference estimates for the 20-meter walk ranged from 4.1 to 6.4 meters/minute and 400-meter walk estimates ranged from 2.9 to 6.5 meters/minute. Prevalent (cross-sectional) anchor-based estimates for the 20-meter walk ranged from 5.4 to 6.9 meters/minute and for the 400-meter walk ranged from 3.0 to 6.9 meters/minute. Longitudinal anchor-based estimates were deemed unreliable. Combining distribution-based with prevalent anchor-based methods showed that an important gait speed difference for the 20-meter walk is between 4.1 and 6.9 meters/minute and for the 400-meter walk is between 2.9 and 6.9 meters/minute. Our results found that the important difference in gait speed for the 20-meter walk and the 400-meter walk is consistent with important difference estimates for older adult populations. These findings can provide benchmarks for assessing and understanding functional performance outcomes when comparing exposure groups and can be used in designing future studies targeting adults with radiographic knee osteoarthritis.

The effect of the interaction between fall-related self-efficacy and gait function on the occurrence of falls in community-dwelling older people

BackgroundFall-related self-efficacy and gait function are known to be associated. However, whether the interaction between fall-related self-efficacy and gait function affects future falls has not been investigated.AimThe aim of this study was to investigate the effect of the interaction between fall-related self-efficacy and spatiotemporal gait parameters on the occurrence of falls in community-dwelling older people.MethodsA total of 265 elderly persons (age ≥ 65 years) living independently in the community were recruited. For gait function, spatiotemporal gait parameters at usual and maximum effort paces were measured using a 2.4-m walkway system with embedded pressure sensors. Furthermore, changes in gait parameters between usual and maximum paces were calculated (Δgait parameters). Fall-related self-efficacy was assessed using the short version of the Falls Efficacy Scale International (Short FES-I). The occurrence of falls was prospectively investigated 6 months later. The effect of the interaction between short FES-I and gait parameters on falls was analyzed using logistic regression analysis adjusted for confounding factors.ResultsSeveral gait parameters were significantly different by self-efficacy level. As for the effect of the interaction of fall-related self-efficacy and gait parameters on falls, smaller Δgait parameters in those with high efficacy were associated with higher odds ratios of falls, whereas Δgait parameters in those with low efficacy were not associated with falls.Discussion and conclusionsThe interaction between fall-related self-efficacy and gait function appeared to affect future falls. Assessments combining fall-related self-efficacy and gait function may improve the accuracy of prediction of future falls.

Rivastigmine improves dual-task gait velocity in patients with Alzheimer\u2019s disease

BackgroundGait impairments are common in patients with Alzheimer’s disease. Cholinesterase inhibitors are used to treat the symptoms of patients with Alzheimer’s disease, but they have not been shown to reduce the severity of Alzheimer’s disease-related gait disorders.MethodsThis was a prospective, single-arm, open-label, non-randomized study. The aim of the present study was to determine the effect of the acetylcholinesterase inhibitor rivastigmine on gait in 21 newly diagnosed patients with mild to moderate Alzheimer’s disease. The outcome variables were velocity, stride length, and cadence during single-task and dual-task gait trials. The subjects were also assessed with the Mini-Mental State Examination, Alzheimer’s Disease Cooperative Study Activities of Daily Living, Functional Assessment Staging, and Geriatric Depression Scale.ResultsAfter 12 weeks of treatment with rivastigmine, gait velocity was significantly improved in the dual-task gait trials; gait velocity was increased from 40.59 ± 13.59 m/min at baseline to 46.88 ± 12.73 m/min when counting backward from 100 in steps of 7 while walking, and gait velocity was increased from 37.06 ± 15.57 m/min at baseline to 42.03 ± 14.02 m/min when naming animals while walking. In the single-task gait trials, which consisted only of walking at their usual pace or at a fast pace, gait velocity was not increased by rivastigmine administration.ConclusionOur findings indicated that rivastigmine improved gait in subjects with mild to moderate Alzheimer’s disease during dual-task trials. The observed enhancement of dual-task gait might be caused by an improvement of cognitive function rather than motor function.Trial registrationUMIN, UMIN000025869. Registered December 16, 2016, https://upload.umin.ac.jp/cgi-open-bin/icdr/ctr_view.cgi?recptno=R000029744

Imaging-based indices of Neuropathology and gait speed decline in older adults: the atherosclerosis risk in communities study.

Imaging markers of cerebrovascular disease and Alzheimer's disease (AD) are implicated in mobility impairment in older adults, but few studies have examined these relationships longitudinally in a racially-diverse population-based sample. At Visit 5 (2011-13) of the ARIC Study, 1859 participants had usual pace gait speed (cm/s) assessed and brain MRI (mean age = 76.3, 28.5% Black) and PET (n = 343; mean age = 75.9, 42.6% Black) measures including total/regional brain volume (cm3), white matter hyperintensities (WMH; cm3), infarcts (present/absent), microbleeds (count) and global beta-amyloid (Aβ). Participants returned at Visit 6 (n = 1264, 2016-17) and Visit 7 (n = 1108, 2018-19) for follow-up gait speed assessments. We used linear regression to estimate effects of baseline infarct presence, higher microbleed count, and a one interquartile range (IQR) poorer measures of continuous predictors (-1 IQR total brain volume, temporal-parietal lobe meta region of interest(ROI); +1 IQR WMH volume, global Aβ SUVR) on cross-sectional gait speed and change in gait speed adjusting for age, sex, education, study site, APOE e4, estimated intracranial volume, BMI, and cardiovascular risk factors. Cross-sectionally, slower gait speed outcome was associated with higher WMH volume, -3.38cm/s (95%CI:-4.71, -2.04), infarct presence, -5.60cm/s (-7.69, -3.51), microbleed count, -2.20cm/s (-3.20, -0.91), smaller total brain volume, -9.26cm/s (-12.1, -6.43), and smaller temporal-parietal lobe ROI -6.28cm/s (-8.28, -4.28). Longitudinally, faster gait speed outcome decline was associated with higher WMH volume, -0.27cm/s/year, (-0.51, -0.03) and higher global Aβ SUVR, -0.62cm/s/year (-1.20, -0.03). Both cerebrovascular and AD pathology may contribute to mobility decline commonly seen with aging.

Validity, reliability, and measurement error of a sit-to-stand power test in older adults: A pre-registered study.

Lower body power declines with age and is associated with decreased physical function in older adults. However, the majority of the tools available to measure power are expensive and require considerable space and expertise to operate. The purpose of this study was to assess the validity, reliability, and measurement error of a sit-to-stand power test (STSp) to assess lower body power. 51 community-dwelling adults, 65years or older, completed a power test using a pneumatic leg press (LP), the Short Physical Performance Battery (SPPB) that includes a test of balance, usual walking speed, and chair stand tests; Timed Up and Go (TUG) test at both usual and fast paces, and Patient-Reported Outcome Measures (PROMs). A two-week test-retest assessed the reliability in 36 participants. The study hypotheses and analysis were pre-registered prior to data collection and statistical analyses were blinded. The mean age was 71.3years, with 63% females, and an average SPPB score of 10.6 (median=12). STSp peak power was strongly correlated with LP (r=0.90, 95% CI (0.82, 0.94). As hypothesized, the STSp peak power showed similar or higher correlations with physical function tests relative to LP peak power: SPPB (0.41 vs. 0.29), chair stand test (-0.44 vs. -0.35), TUG test at usual pace (-0.37 vs. -0.29) and fast pace (-0.41 vs. -0.34) and balance (0.33 vs. 0.22), but not for mobility (0.34 vs. 0.38) and function (0.41 vs. 0.48) questionnaire. For discriminant validity, as hypothesized, males showed higher STSp peak power compared to females (Δ=492W, p<.001, Cohen's d=2.0). Test-retest assessment yielded an intraclass correlation coefficient of 0.96 and a standard error of measurement of 70.4W. No adverse events were reported or observed for both tests. The STSp showed adequate validity and reliability in measuring lower body power in community-dwelling older adults. The test is quick, relatively inexpensive, safe, and portable and thus should be considered for use in aging research.

Dopamine-Related Genotype Predicts Trajectories of Gait Reserve in Older Adults

The capacity to increase one’s gait speed is critical for maintaining safe community ambulation. There is limited work on the longitudinal changes in this capacity and its predictors. Because lower dopamine is associated with lower task adaptation and motivation, we hypothesized that lower dopamine would predict more decline in rapid gait speed. Catechol-O-methyltransferase (COMT) polymorphism and at least 3 repeated rapid and usual pace gait speed assessments were obtained over 10 years in 1,261 older adults (mean age=75.2, 867 White, 659 women). Linear mixed models computed person-specific rapid and usual pace gait speed trajectories. Regression models adjusted for usual gait trajectory tested whether COMT predicted rapid gait trajectory; covariates included, demographic, psychological, cognitive, and physical factors. Val/Val carriers (lower dopamine) declined more in rapid gait compared to Met/Met carriers (higher dopamine; adjusted b=-.002, SE=.001, p=.042). Modifying dopamine may positively influence the ability to maintain rapid gait over time.

Multimodal behavioral analysis for early detection of Alzheimer’s disease: A preliminary result

AbstractBackgroundWith the rapid growth in the elderly population worldwide, early detection of Alzheimer’s disease (AD) has become increasingly important. In this respect, behavioral analysis of sensor data is expected to extend opportunities for assessments and help identify subtle changes resulting from AD at an early stage. Gait, speech, and drawing behaviors have been actively investigated and recognized as behavioral biomarkers that can be used for detecting individuals with AD and mild cognitive impairment (MCI). However, previous studies have mainly investigated single types of behavior. It remains unclear whether combining multimodal behavioral data could improve detection performance.MethodIn this study, we collected multimodal behavioral data related to gait, speech, and drawing from 73 Japanese seniors consisting of 36 healthy controls (HC), 26 MCI, and 11 AD. For gait data, we collected motion capture data during 9‐meter walks at the usual walking pace and extracted gait features related to pace, rhythm, variability, and postural control. Speech data were collected while performing tablet‐based cognitive tasks consisting of verbal fluency, calculation, and picture description, followed by extraction of acoustic, prosodic, and linguistic features. We also collected drawing behaviors with a drawing tablet during five tasks including clock drawing and trail making, and obtained features related to kinematic parameters of drawing trajectories and drawing pressure. We then used these features to build binary classification models for differentiating MCI or AD from HC using a support vector machine model with a feature selection method. The models were then evaluated by ten‐fold cross‐validation.ResultOur models using features of three types of behavior achieved 99.8% accuracy for HC vs. AD and 92.0% accuracy for HC vs. MCI. Compared to models using single modality behavioral data, we found that our model improved detection by up to 9.1% for HC vs. AD and 21.0% for HC vs. MCI.ConclusionWe demonstrated that multiple behavioral data could improve detection accuracy for patients with both MCI and AD by capturing different functional changes resulting from AD. Our approach based on multimodal behavioral analysis shows promise for timely diagnosis at an early stage of AD.

Catechol-O-Methyltransferase Genotype, Frailty, and Gait Speed in a Biracial Cohort of Older Adults.

To examine whether the association between dopamine-related genotype and gait speed differs according to frailty status or race. Cross-sectional population-based study (Cardiovascular Health Study). Multicenter study, four U.S. sites. Volunteer community-dwelling adults aged 65 years and older, without evidence of Parkinson's disease (N = 3,744; 71 years; 82% White; 39% male). Gait speed (usual pace; m/s), physical frailty (Fried definition), and genetic polymorphism of catechol-O-methyltransferase (COMT; rs4680), an enzyme regulating tonic brain dopamine levels, were assessed. Interaction of COMT by frailty and by race predicting gait speed were tested, and, if significant, analyses were stratified. Multivariable regression models of COMT predicting gait speed were adjusted for demographics and locomotor risk factors. Sensitivity analyses were repeated, stratified by clinical cutoffs of gait speed (0.6 and 1.0 m/s) instead of frailty status. The interaction of COMT by frailty and COMT by race were P = .02 and P = .01, respectively. Compared with Met/Met (higher dopaminergic signaling), the Val/Val group (lower dopaminergic signaling) walked marginally more slowly in the full cohort (0.87 vs 0.89 m/s; P = .2). Gait speed differences were significant for frail (n = 220; 0.55 vs 0.63 m/s; P = .03), but not for prefrail (n = 1,691; 0.81 vs 0.81 m/s; P = .9) or nonfrail (n = 1,833; 0.98 vs 0.97 m/s; P = .7); results were similar in fully adjusted models. Among frail, associations were similar for Whites and Blacks, with statistical significance for Whites only. Associations stratified by clinical cutoffs of gait speed were not significant. The association of dopamine-related genotype with gait speed is stronger among adults with frailty compared with those without frailty. The potential effects of dopaminergic signaling on preserving physical function in biracial cohorts of frail adults should be further examined.

Formative Evaluation of Consumer-Grade Activity Monitors Worn by Older Adults: Test-Retest Reliability and Criterion Validity of Step Counts.

BackgroundTo assess whether commercial-grade activity monitors are appropriate for measuring step counts in older adults, it is essential to evaluate their measurement properties in this population.ObjectiveThis study aimed to evaluate test-retest reliability and criterion validity of step counting in older adults with self-reported intact and limited mobility from 6 commercial-grade activity monitors: Fitbit Charge, Fitbit One, Garmin vívofit 2, Jawbone UP2, Misfit Shine, and New-Lifestyles NL-1000.MethodsFor test-retest reliability, participants completed two 100-step overground walks at a usual pace while wearing all monitors. We tested the effects of the activity monitor and mobility status on the absolute difference in step count error (%) and computed the standard error of measurement (SEM) between repeat trials. To assess criterion validity, participants completed two 400-meter overground walks at a usual pace while wearing all monitors. The first walk was continuous; the second walk incorporated interruptions to mimic the conditions of daily walking. Criterion step counts were from the researcher tally count. We estimated the effects of the activity monitor, mobility status, and walk interruptions on step count error (%). We also generated Bland-Altman plots and conducted equivalence tests.ResultsA total of 36 individuals participated (n=20 intact mobility and n=16 limited mobility; 19/36, 53% female) with a mean age of 71.4 (SD 4.7) years and BMI of 29.4 (SD 5.9) kg/m2. Considering test-retest reliability, there was an effect of the activity monitor (P<.001). The Fitbit One (1.0%, 95% CI 0.6% to 1.3%), the New-Lifestyles NL-1000 (2.6%, 95% CI 1.3% to 3.9%), and the Garmin vívofit 2 (6.0%, 95 CI 3.2% to 8.8%) had the smallest mean absolute differences in step count errors. The SEM values ranged from 1.0% (Fitbit One) to 23.5% (Jawbone UP2). Regarding criterion validity, all monitors undercounted the steps. Step count error was affected by the activity monitor (P<.001) and walk interruptions (P=.02). Three monitors had small mean step count errors: Misfit Shine (−1.3%, 95% CI −19.5% to 16.8%), Fitbit One (−2.1%, 95% CI −6.1% to 2.0%), and New-Lifestyles NL-1000 (−4.3%, 95 CI −18.9% to 10.3%). Mean step count error was larger during interrupted walking than continuous walking (−5.5% vs −3.6%; P=.02). Bland-Altman plots illustrated nonsystematic bias and small limits of agreement for Fitbit One and Jawbone UP2. Mean step count error lay within an equivalence bound of ±5% for Fitbit One (P<.001) and Misfit Shine (P=.001).ConclusionsTest-retest reliability and criterion validity of step counting varied across 6 consumer-grade activity monitors worn by older adults with self-reported intact and limited mobility. Walk interruptions increased the step count error for all monitors, whereas mobility status did not affect the step count error. The hip-worn Fitbit One was the only monitor with high test-retest reliability and criterion validity.

Gait speed, life-space mobility and mild cognitive impairment in patients with coronary artery disease.

Slow gait speed and restricted life-space mobility predict cognitive decline and dementia in healthy older adults, yet the relation between gait speed or life-space mobility and cognitive function remains poorly understood in patients with coronary artery disease (CAD). We, therefore, examined the following relations: that between gait speed and cognitive function, and mild cognitive impairment (MCI) and that between life-space mobility and cognitive function, and MCI. We conducted a cross-sectional study of 240 non-dementia patients who met the study criteria from 2132 consecutive CAD patients. MCI was estimated with the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Gait speed was measured to perform gait trials at the patients' usual walking pace, and life-space mobility was evaluated using the Life-Space Assessment (LSA). We investigated the relation between gait speed or life-space mobility and cognitive function by Pearson correlation analysis, whereas multivariable logistic regression analysis was conducted for detecting MCI. Gait speed and LSA scores were positively associated with the MoCA-J score (r = 0.54, p < 0.001 and r = 0.44, p < 0.001, respectively), and both were independently associated with MCI in the multivariable logistic regression analysis (odds ratio 0.007, p < 0.001, and odds ratio 0.98, p = 0.038, respectively). Cognitive impairment can be easily detected by assessment of gait speed and life-space mobility. Interventions to improve gait speed and life-space mobility may lead to the improvement of cognitive function and MCI in patients with CAD.

Musculoskeletal Injuries In Charity Team Marathoners Training For The Boston Marathon

PURPOSE: There is a gap in the sports medicine literature about injury types and rates in runners training for a marathon with a charity team. Our objectives were to: 1. Determine the types of injuries among members of a charity marathon team, and 2. Estimate the rates of injuries in this group. METHODS: This is a survey study with a secondary medical record review of the 2019 Stepping Strong charity marathon team at Brigham and Women’s Hospital, Boston, MA (140 runners). Measures were: 1. Self-report baseline questionnaire, and 2. Symptom and function inventory questionnaires completed during the training cycle and after the Boston Marathon. We generated descriptive statistics and determined injury types and rates from these measures. RESULTS: Participants had a mean of 10.2 (SD 8.8) years of running experience, and most commonly averaged 10 to 19.9 miles per week (41.8%). The mean number of previous marathons trained for and completed was 5 (SD 10.3), and 94.9% raised $7,500.00 or more. 26.3% of runners reported a medical-provider diagnosed injury, 43.8% reported an injury not diagnosed by a medical provider lasting more than 1 week, 40% reported pain due to running lasting more than 1 week, and 53.8% reported pain due to running of any duration. Injury locations are displayed in Figure 1. More than 50% of runners reported pain that interfered with their ability to run their usual distance at their usual pace, and approximately 25% of runners reported pain that interfered with their ability to walk. 76% of respondents to the post-race questionnaire reported they developed pain at some point during the marathon training cycle, and 88% of respondents indicated they would run a marathon again. CONCLUSIONS: Less stringent injury definitions resulted in greater percentages of participants reporting injuries. The knee, foot and hip were common injury sites. Though most participants developed pain during the marathon training cycle, almost all indicated they would run a marathon again.

Predicting Adverse Outcomes in Healthy Aging Community-Dwelling Early-Old Adults with the Timed Up and Go Test.

BackgroundSimple, easy-to-perform, safe and cost-effective methods for the prediction of adverse outcomes in older adults are essential for the identification of patients who are most likely to benefit from early preventive interventions.MethodsThe study included 160 community-dwelling individuals aged 60–74 years, with 44.4% women. A comprehensive geriatric assessment was performed in all participants. Bioimpedance body composition analysis included 149 subjects. Among other tests, functional assessment included the Barthel Index of Activities of Daily Living (Barthel Index), Mini-Mental State Examination (MMSE), Timed Up and Go (TUG) and Fried frailty phenotype. Follow-up by telephone was made after at least 365 days. The composite endpoint (CE) included fall, hospitalization, institutionalization and death.ResultsCohort characteristics: age 66.8±4.2 years (mean±SD), 3.81±2.23 diseases, 4.29±3.60 medications or supplements, and good functional status (MMSE 29.0±1.5, Barthel Index 98.1±8.2, prevalence of Fried frailty phenotype 2.5%). During one-year follow-up, 34 subjects (21.3%; 95% confidence interval [CI] =14.9−27.6%) experienced CE: hospitalizations (13.8%; 95% CI=8.41−19.1), falls (9.38%; 95% CI=4.86−13.9), death (0.63%; 95% CI=0−1.85) and no institutionalization. A higher probability of CE was associated with age ≥70 years (P=0.018), taking any medication or supplements (P=0.007), usual pace gait speed ≤0.8 m/s (P=0.028) and TUG >9 s (P<0.002). TUG was the only independent measure predicting one-year CE occurrence (OR=1.22, 95% CI=1.07−1.40, P=0.003) in multivariate logistic regression. However, its predictive power was poor; the area under the receiver operating characteristic curve was 0.659 (95% CI 0.551−0.766, P=0.004) and Youden’s J statistic for a TUG cut-off of 9.0 s was 0.261 (sensitivity 0.618 and specificity 0.643).ConclusionThe TUG test was superior to frailty phenotype measures in predicting one-year incidence of a CE consisting of fall, hospitalization, institutionalization and death in a cohort of healthy-aging community-dwelling early-old adults, although its value as a stand-alone test was limited.

Walking Speed Affects Gait Coordination and Variability Among Older Adults With and Without Mobility Limitations

ObjectiveTo determine if poorer gait variability and gait coordination among mobility-limited older adults is related to their slower walking speed. DesignCross-sectional analysis. SettingUniversity research laboratory. ParticipantsCommunity-dwelling adults (N=69) 68 years or older with (Short Physical Performance Battery score ≤9; n=37) and without (n=32) mobility limitations. InterventionsNot applicable. Main Outcome MeasuresThe variability of step length, swing time percent, and step width. Gait coordination was assessed along with the Phase Coordination Index. ResultsThe usual pace gait speed of those without mobility limitations was faster (1.22±0.14m/s vs 0.71±0.14m/s; P<.001) and less variable in all gait characteristics (all P<.001), with the exception of step width (P=.185), than those with limitations. When those without limitations slowed their walking pace (0.71m/s±0.14), their gait coordination became poorer (P<.001), and the variability of all gait characteristics increased (all P<.001) except for step width, which decreased (P=.002). When those without mobility limitations walked at a slow pace, they had better gait coordination (P=.008) and less variable step length (P=.014) and swing time percent (P=.036). The variability of stride time (P=.260) and step width (P=.385) were not significantly different than that of their peers with limitations. ConclusionsIncreased variability in some gait characteristics of mobility-limited older adults appears to be related to their slower walking speed. Gait coordination and the variability of step length and swing time percent may reflect intrinsic differences in mobility-limited older adults that are independent of walking speed.

Measuring Slowness in Old Age: Times to Perform Moberg Picking-Up and Walking Speed Tests

ObjectivesSlowness is a marker of frailty captured by the Fried phenotype by a walking speed test which, for health or logistical reasons, is sometimes difficult to perform. The Moberg picking-up test (MPUT) is another timed functional test. It measures hand motor activity and might represent an alternative to assess slowness when the walking speed cannot be evaluated. This study aimed to evaluate the relationship between MPUT and walking speed. DesignCross-sectional. Setting and ParticipantsIn total, 2748 individuals aged 66 to 83 years who participated in the latest examination (2015-2017) of the population-based Lausanne cohort 65+ and completed both tests. MethodsWalking speed (time to walk 20 meters at usual pace) and MPUT (time to pick up 12 objects) were compared using scatter graphs. Multivariate regression models further investigated the relationship between MPUT and walking times with adjustment for height, grip strength, body mass index, and Mini-Mental State Examination. All analyses were stratified by sex. ResultsMPUT and walking times were moderately, positively correlated in men (r = 0.38, P < .001) and in women (r = 0.38, P < .001). Higher grip strength and Mini-Mental State Examination performances were correlated to shorter MPUT and walking times. Men and women slower at the MPUT were also significantly slower at the walking speed test when adjusting for height (P < .001) as well as in fully adjusted models (P < .001). Conclusions and ImplicationsThese preliminary results point to a positive association between MPUT and walking speed independent of muscle strength and cognition. Further research is needed to investigate the capacity of MPUT to predict adverse health outcomes before considering this test as an alternative measure of slowness in the assessment of frailty.

Individual and joint trajectories of change in bone, lean mass and physical performance in older men

BackgroundDeclines in bone, muscle and physical performance are associated with adverse health outcomes in older adults. However, few studies have described concurrent age-related patterns of change in these factors. The purpose of this study was to characterize change in four properties of muscle, physical performance, and bone in a prospective cohort study of older men.MethodsUsing repeated longitudinal data from up to four visits across 6.9 years from up to 4681 men (mean age at baseline 72.7 yrs. ±5.3) participating in the Osteoporotic Fractures in Men (MrOS) Study, we used group-based trajectory models (PROC TRAJ in SAS) to identify age-related patterns of change in four properties of muscle, physical performance, and bone: total hip bone mineral (BMD) density (g/m2) and appendicular lean mass/ht2 (kg/m2), by DXA; grip strength (kg), by hand dynamometry; and walking speed (m/s), by usual walking pace over 6 m. We also described joint trajectories in all pair-wise combinations of these measures. Mean posterior probabilities of placement in each trajectory (or joint membership in latent groups) were used to assess internal reliability of the model. The number of trajectories for each individual factor was limited to three, to ensure that the pair-wise determination of joint trajectories would yield a tractable number of groups as well as model fit considerations.ResultsThe patterns of change identified were generally similar for all measures, with three district groups declining over time at roughly similar rates; joint trajectories revealed similar patterns with no cross-over or convergence between groups. Mean posterior probabilities for all trajectories were similar and consistently above 0.8 indicating reasonable model fit to the data.ConclusionsOur description of trajectories of change with age in bone mineral density, grip strength, walking speed and appendicular lean mass found that groups identified by these methods appeared to have little crossover or convergence of change with age, even when considering joint trajectories of change in these factors.

Grip Strength and Walking Pace and Cardiovascular Disease Risk Prediction in 406,834 UK Biobank Participants

ObjectiveTo investigate whether the addition of grip strength and/or self-reported walking pace to established cardiovascular disease (CVD) risk scores improves their predictive abilities. Patients and MethodsA total of 406,834 participants from the UK Biobank, with baseline measurements between March 13, 2006, and October 1, 2010, without CVD at baseline were included in this study. Associations of grip strength and walking pace with CVD outcomes were investigated using Cox models adjusting for classical risk factors (as included in established risk scores), and predictive utility was determined by changes in C-index and categorical net reclassification index. ResultsOver a median of 8.87 years of follow-up (interquartile range 3, 8.25-9.47 years), there were 7274 composite fatal/nonfatal events (on the basis of the American College of Cardiology/American Heart Association [ACC/AHA] outcome) and 1955 fatal events (on the basis of the Systematic Coronary Risk Evaluation [SCORE] risk score). Both grip strength and walking pace were inversely associated with CVD outcomes after adjusting for classical risk factors. Addition of grip strength (change in C-index: ACC/AHA, +0.0017; SCORE, +0.0047), usual walking pace (ACC/AHA, +0.0031; SCORE, +0.0130), and both combined (ACC/AHA, +0.0041; SCORE, +0.0148) improved the C-index and also improved the net reclassification index (grip, +0.55%; walking pace, +0.53%; combined, 1.12%). ConclusionThe present study has found that the addition of grip strength or usual walking pace to existing risk scores results in improved CVD risk prediction, with an additive effect when both are added. As both these measures are cheap and easy to administer, these tools could provide an important addition to CVD risk screening, although further external validation is required.