Accuracy of Thresholds Based on Cadence and Lifestyle Counts per Minute to Detect Outdoor Walking in Older Adults With Mobility Limitations

Objective: To determine the optimal threshold, based on cadence and lifestyle counts per minute, to detect outdoor walking in mobility-limited older adults. Methods: Older adults (N = 25, median age: 77.0 years, interquartile range: 10.5) wore activity monitors during 80 outdoor walks. Walking bouts were identified manually (reference standard) and compared with identification using cadence thresholds (≥30, ≥35, ≥40, ≥45, and ≥50 steps/min) and >760 counts per minute using low frequency extension analysis. Results: Median walking bout duration was 10.5 min (interquartile range 4.8) and median outdoor walking speed was 0.70 m/s (interquartile range 0.20). Cadence thresholds of ≥30, ≥35, and ≥40 steps/min demonstrated high sensitivity (1.0, 95% confidence intervals [0.95, 1.0]) to detect walking bouts; estimates for specificity and positive predictive value were highest for ≥40 steps/min. Conclusion: A cadence threshold of ≥40 steps/min is recommended for detecting sustained outdoor walking in this population.

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

Archives of Physical Medicine and Rehabilitation ◽

10.1016/j.apmr.2020.04.009 ◽

2020 ◽

Vol 101 (8) ◽

pp. 1377-1382

Author(s):

Eric G. James ◽

Phillip Conatser ◽

Murat Karabulut ◽

Suzanne G. Leveille ◽

Jeffrey M. Hausdorff ◽

...

Keyword(s):

Older Adults ◽

Walking Speed ◽

Mobility Limitations ◽

Gait Coordination

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Agreement Between StepWatch3 and ActiGraph wGT3X+ for Measuring Step-Based Metrics in People With Peripheral Artery Disease

Journal of Aging and Physical Activity ◽

10.1123/japa.2020-0499 ◽

2021 ◽

pp. 1-12

Author(s):

Pierre Jéhannin ◽

Alexis Le Faucheur ◽

Ségolène Chaudru ◽

Aline Taoum ◽

Guillaume Mahé ◽

...

Keyword(s):

Older Adults ◽

Peripheral Artery Disease ◽

Low Frequency ◽

Step Count ◽

Peripheral Artery ◽

Free Living ◽

Outdoor Walking ◽

Artery Disease

The authors investigated the agreement between StepWatch3™ (SW3) and ActiGraph™ wGT3X+ monitors for measuring step-based metrics in patients with peripheral artery disease and older adults. In 23 patients with peripheral artery disease and 38 older participants, the authors compared the metrics obtained during an outdoor (400-m track) walking session (step count) and a 7-day free-living period (step count and 60/30/5/1-min maximal or peak step accumulation) using the SW3 (ankle) and the wGT3X+ (hip) with the low-frequency extension filter enabled (wGT3X+/LFE) or not (wGT3X+/N). During outdoor walking session, agreement was high, particularly for wGT3X+/LFE: correlations ≥.98, median absolute percentage errors <1%, and significant equivalence using a ± 15% equivalence zone or narrower. In free living, no wGT3X+ method was equivalent to SW3 for step count. The wGT3X+/LFE was equivalent to SW3 regarding all step accumulation metrics using a ± 20% equivalence zone or narrower, with median absolute percentage errors <11%. The wGT3X+/LFE method is the best option for comparisons with SW3 in peripheral artery disease and older adults.

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Outdoor walking exhibits peak ankle and knee flexion differences compared to fixed and adaptive-speed treadmills in older adults

BioMedical Engineering OnLine ◽

10.1186/s12938-021-00941-0 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Sheridan M. Parker ◽

Jeremy Crenshaw ◽

Nathaniel H. Hunt ◽

Christopher Burcal ◽

Brian A. Knarr

Keyword(s):

Older Adults ◽

Knee Flexion ◽

Walking Speed ◽

Sagittal Plane ◽

Measurement Unit ◽

Adult Participants ◽

Peak Knee ◽

Outdoor Walking ◽

Hip Flexion ◽

Walking Speeds

Abstract Background Walking mechanics recorded with a traditional treadmill may not be the same as the mechanics exhibited during activities of daily living due to constrained walking speeds. Adaptive-speed treadmills allow for unconstrained walking speeds similar to outdoor walking. The aim of this study was to determine differences in kinematic walking parameters of older adults between adaptive-speed treadmill (AST), fixed-speed treadmill (FST) and outdoor walking. We hypothesized that self-selected walking speed (SSWS) during AST walking and outdoor walking would increase compared to FST walking. Furthermore, we hypothesized that AST walking and outdoor walking would increase peak knee flexion, hip flexion, and ankle plantarflexion angles compared to FST walking independent of walking speed changes. Methods Fourteen older adult participants were asked to complete 3 min of FST and AST walking on a split-belt treadmill. Participants were also asked to complete 6 min of outdoor walking following a circular route in a neighboring park. A wireless inertial measurement unit-based motion capture system was used to record lower extremity kinematics during all walking conditions. Results The outdoor walking condition produces significantly higher SSWS compared to FST (p < 0.001) and AST (p = 0.02) conditions. A significantly faster SSWS was exhibited during the AST condition compared to the FST condition (p = 0.026). Significantly higher peak ankle plantarflexion angles are exhibited during the outdoor walking condition compared to the AST (p < 0.001, g = 1.14) and FST (p < 0.001, g = 1.13) conditions after accounting for walking speed. There was a significantly lowered difference between the outdoor walking condition and both AST (p = 0.029, g = 0.49) and FST (p = 0.013, g = 0.63) conditions in peak knee flexion angles after accounting for SSWS. There are no significant differences between outdoor, AST, and FST conditions on peak hip flexion angles. Older adults exhibit changes in peak ankle plantarflexion and peak knee flexion angles during outdoor walking compared to treadmill walking but not between treadmill controller types. We found no differences in the kinematics exhibited by older adults between both AST and FST walking. Conclusions Incorporating unconstrained walking speed with the AST while maintaining similar FST sagittal plane kinematics may allow for more translatable conditional balance and walking rehabilitation.

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Intra-day variation in daily outdoor walking speed among community-dwelling older adults

BMC Geriatrics ◽

10.1186/s12877-021-02349-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Hisashi Kawai ◽

Shuichi Obuchi ◽

Ryo Hirayama ◽

Yutaka Watanabe ◽

Hirohiko Hirano ◽

...

Keyword(s):

Older Adults ◽

Latent Class ◽

Walking Speed ◽

Daily Life ◽

Community Dwelling ◽

Factors Associated ◽

Significant Difference ◽

Outdoor Walking ◽

Time Periods ◽

Community Dwelling Older Adults

Abstract Background Walking speed is an important measure associated with health outcomes in older individuals, such as dependency and death. This study aimed to examine whether the walking speed of community-dwelling older adults varies between time periods within a day, as measured outdoors in daily life. We aimed to determine the types of walking speed variations and examine the factors associated with them. Methods Daily life outdoor walking speed was measured in 92 participants (average age 71.9 years±5.64) using a GPS smartphone app for 1 month. Average walking speeds for five time periods were analyzed with a linear mixed model. Intra-day walking speed variation patterns were classified by latent class analysis. Factors associated with the class were identified by logistic regression analysis. Results A statistically significant difference in average walking speed was found between early morning (1.33 m/s), and afternoon (1.27 m/s) and evening (1.26 m/s) (p < 0.01). The intra-day variation in walking speed was attributed to variation in cadence. Two classes were identified: (1) fast walking speed with large variation and (2) slow walking speed with little variation; hypertension and frailty level were associated with the class. Conclusion The results suggest that there is intra-day variation in walking speed in daily life, wherein the speed is the fastest early in the morning and slower in the afternoon and evening. A larger variation in the walking speed was related to the health status without hypertension or frailty. These results suggest that if a person shows less intra-day variation in walking speed, this could be a sign that they are susceptible to hypertension and an increased frailty level.

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Magnetoelastic Coupling and Delta-E Effect in Magnetoelectric Torsion Mode Resonators

Sensors ◽

10.3390/s21062022 ◽

2021 ◽

Vol 21 (6) ◽

pp. 2022

Author(s):

Benjamin Spetzler ◽

Elizaveta V. Golubeva ◽

Ron-Marco Friedrich ◽

Sebastian Zabel ◽

Christine Kirchhof ◽

...

Keyword(s):

Low Frequency ◽

High Sensitivity ◽

Element Model ◽

Mode Number ◽

Frequency Change ◽

General Description ◽

Resonance Modes ◽

Field Sensor ◽

Magnetic Sensitivity ◽

Bending Modes

Magnetoelectric resonators have been studied for the detection of small amplitude and low frequency magnetic fields via the delta-E effect, mainly in fundamental bending or bulk resonance modes. Here, we present an experimental and theoretical investigation of magnetoelectric thin-film cantilevers that can be operated in bending modes (BMs) and torsion modes (TMs) as a magnetic field sensor. A magnetoelastic macrospin model is combined with an electromechanical finite element model and a general description of the delta-E effect of all stiffness tensor components Cij is derived. Simulations confirm quantitatively that the delta-E effect of the C66 component has the promising potential of significantly increasing the magnetic sensitivity and the maximum normalized frequency change ∆fr. However, the electrical excitation of TMs remains challenging and is found to significantly diminish the gain in sensitivity. Experiments reveal the dependency of the sensitivity and ∆fr of TMs on the mode number, which differs fundamentally from BMs and is well explained by our model. Because the contribution of C11 to the TMs increases with the mode number, the first-order TM yields the highest magnetic sensitivity. Overall, general insights are gained for the design of high-sensitivity delta-E effect sensors, as well as for frequency tunable devices based on the delta-E effect.

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Enhanced specificity of clinical high-sensitivity tumor mutation profiling in cell-free DNA via paired normal sequencing using MSK-ACCESS

Nature Communications ◽

10.1038/s41467-021-24109-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

A. Rose Brannon ◽

Gowtham Jayakumaran ◽

Monica Diosdado ◽

Juber Patel ◽

Anna Razumova ◽

...

Keyword(s):

Cancer Patients ◽

De Novo ◽

Low Frequency ◽

High Sensitivity ◽

Clinical Analysis ◽

De Novo Mutation ◽

Cell Free Dna ◽

Free Dna ◽

Somatic Alterations ◽

Mutation Profiling

AbstractCirculating cell-free DNA from blood plasma of cancer patients can be used to non-invasively interrogate somatic tumor alterations. Here we develop MSK-ACCESS (Memorial Sloan Kettering - Analysis of Circulating cfDNA to Examine Somatic Status), an NGS assay for detection of very low frequency somatic alterations in 129 genes. Analytical validation demonstrated 92% sensitivity in de-novo mutation calling down to 0.5% allele frequency and 99% for a priori mutation profiling. To evaluate the performance of MSK-ACCESS, we report results from 681 prospective blood samples that underwent clinical analysis to guide patient management. Somatic alterations are detected in 73% of the samples, 56% of which have clinically actionable alterations. The utilization of matched normal sequencing allows retention of somatic alterations while removing over 10,000 germline and clonal hematopoiesis variants. Our experience illustrates the importance of analyzing matched normal samples when interpreting cfDNA results and highlights the importance of cfDNA as a genomic profiling source for cancer patients.

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Polish Translation and Validation of the Mini Sarcopenia Risk Assessment (MSRA) Questionnaire to Assess Nutritional and Non-Nutritional Risk Factors of Sarcopenia in Older Adults

Nutrients ◽

10.3390/nu13041061 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1061

Author(s):

Roma Krzymińska-Siemaszko ◽

Ewa Deskur-Śmielecka ◽

Arkadiusz Styszyński ◽

Katarzyna Wieczorowska-Tobis

Keyword(s):

Risk Factors ◽

Older Adults ◽

Risk Assessment ◽

Predictive Value ◽

High Sensitivity ◽

Community Dwelling ◽

Nutritional Risk ◽

Polish Language ◽

Community Dwelling Older Adults ◽

Translation And Validation

A simple, short, cheap, and reasonably sensitive and specific screening tool assessing both nutritional and non-nutritional risk factors for sarcopenia is needed. Potentially, such a tool may be the Mini Sarcopenia Risk Assessment (MSRA) Questionnaire, which is available in a seven-item (MSRA-7) and five-item (MSRA-5) version. The study’s aim was Polish translation and validation of both MSRA versions in 160 volunteers aged ≥60 years. MSRA was validated against the six sets of international diagnostic criteria for sarcopenia used as the reference standards. PL-MSRA-7 and PL-MSRA-5 both had high sensitivity (≥84.9%), regardless of the reference standard. The PL-MSRA-5 had better specificity (44.7–47.2%) than the PL-MSRA-7 (33.1–34.7%). Both questionnaires had similarly low positive predictive value (PL-MSRA-5: 17.9–29.5%; PL-MSRA-7: 14.4–25.2%). The negative predictive value was generally high for both questionnaires (PL-MSRA-7: 89.8–95.9%; PL-MSRA-5: 92.3–98.5%). PL-MSRA-5 had higher accuracy than the PL-MSRA-7 (50.0–55% vs. 39.4–45%, respectively). Based on the results, the Mini Sarcopenia Risk Assessment questionnaire was successfully adopted to the Polish language and validated in community-dwelling older adults from Poland. When compared with PL-MSRA-7, PL-MSRA-5 is a better tool for sarcopenia risk assessment.

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Energy Availability And Walking Speed In Older Adults: A Key To Mobility?

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000384916.21798.60 ◽

2010 ◽

Vol 42 ◽

pp. 48

Author(s):

Jennifer A. Schrack ◽

Eleanor M. Simonsick ◽

Paulo H.M. Chaves ◽

Luigi Ferrucci

Keyword(s):

Older Adults ◽

Walking Speed ◽

Energy Availability

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Older Adults’ Adoption of Mobility Devices: Interplay of Predisposing Factors and Precipitating Health Events

Innovation in Aging ◽

10.1093/geroni/igaa057.1567 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

pp. 484-485

Author(s):

Farhanaz Sharmin ◽

Laura Sands

Keyword(s):

Older Adults ◽

Logistic Regression ◽

Chronic Conditions ◽

High School Education ◽

Living Alone ◽

Mobility Limitations ◽

Chi Square ◽

Health Events ◽

Mobility Devices ◽

History Of

Abstract Existing mobility limitations and chronic conditions increase likelihood of adopting mobility-related devices such as canes and walkers. Prior research has not considered how recent acute events such as falls and hospitalizations contribute to the adoption of mobility devices. We studied 4,592 older adults who responded to the 2015 and 2016 National Health and Aging Trends Study surveys, and classified adoption of mobility devices as: (i) Never users (did not use mobility devices either year) and (ii) New users (started using mobility devices in 2016). We determined through chi-square tests, that predisposing characteristics from 2015 that were significantly associated with being a New User in 2016 were: being female, aged 80+, minority race, having a high-school education or lower, living alone, being obese, and having a history of dementia, arthritis, stroke, mobility difficulties, falls, and hospitalization (all P’s<0.05). We used logistic regression to determine the contribution of recent precipitating events on the adoption of mobility devices among older adults after controlling for 2015 characteristics that were significantly associated with being a New user. Precipitating events were significantly associated with being a New user of mobility equipment. Specifically, older adults who, between the 2015 and 2016 interviews, experienced a fall (OR=1.7; 95% CI=1.1-2.9), hospitalization (OR=3.7; 95% CI=2.3-5.9) or increase in mobility difficulties (OR=3.7; 95% CI=2.3-5.9) were more likely to be New users. Study findings reveal the importance precipitating events on the adoption of mobility devices, signaling the importance of assessing for need for mobility devices after these events.

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Effect of Aerobic Exercise Training and Essential Amino Acid Supplementation for 24 Weeks on Physical Function, Body Composition, and Muscle Metabolism in Healthy, Independent Older Adults: A Randomized Clinical Trial

The Journals of Gerontology Series A ◽

10.1093/gerona/gly109 ◽

2018 ◽

Vol 74 (10) ◽

pp. 1598-1604 ◽

Cited By ~ 11

Author(s):

Melissa M Markofski ◽

Kristofer Jennings ◽

Kyle L Timmerman ◽

Jared M Dickinson ◽

Christopher S Fry ◽

...

Keyword(s):

Older Adults ◽

Clinical Trial ◽

Body Composition ◽

Protein Synthesis ◽

Muscle Strength ◽

Randomized Clinical Trial ◽

Walking Speed ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Before And After

Abstract Background Essential amino acids (EAA) and aerobic exercise (AE) acutely and independently stimulate skeletal muscle protein anabolism in older adults. Objective In this Phase 1, double-blind, placebo-controlled, randomized clinical trial, we determined if chronic EAA supplementation, AE training, or a combination of the two interventions could improve muscle mass and function by stimulating muscle protein synthesis. Methods We phone-screened 971, enrolled 109, and randomized 50 independent, low-active, nonfrail, and nondiabetic older adults (age 72 ± 1 years). We used a 2 × 2 factorial design. The interventions were: daily nutritional supplementation (15 g EAA or placebo) and physical activity (supervised AE training 3 days/week or monitored habitual activity) for 24 weeks. Muscle strength, physical function, body composition, and muscle protein synthesis were measured before and after the 24-week intervention. Results Forty-five subjects completed the 24-week intervention. VO2peak and walking speed increased (p < .05) in both AE groups, irrespective of supplementation type, but muscle strength increased only in the EAA + AE group (p < .05). EAA supplementation acutely increased (p < .05) muscle protein synthesis from basal both before and after the intervention, with a larger increase in the EAA + AE group after the intervention. Total and regional lean body mass did not change significantly with any intervention. Conclusions In nonfrail, independent, healthy older adults AE training increased walking speed and aerobic fitness, and, when combined with EAA supplementation, it also increased muscle strength and EAA-stimulated muscle protein synthesis. These increases occurred without improvements in muscle mass.

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