Taoist way of a balanced exercise training cocktail for the management of primary hypertension in older persons

High blood pressure is the world's leading risk factor for mortality, affecting nearly half of the global population aged 50-79 years. Physical inactivity is one factor contributing to the prevalence of hypertension. This paper discusses a new concept for the management of hypertension in older persons. We are inclined to fade the current guidelines used in China, the United States, and Europe. Although demonstrating irrefutable benefits for blood pressure regulation, the guidelines fail to address the need to incorporate balance exercises, which are crucial for mitigating the risk of falling. We address three pressing questions regarding the efficacy of various combinations of exercise modes for blood pressure regulation, alongside providing an overview of balance exercises. At the core of our concept, we explicate the challenges inherent in addressing the global pandemic of physical inactivity and hypertension in regular socioeconomic people. No guidelines could change the state of inactivity by jumping between zero and all things, where "zero" symbolizes conditions such as physical inactivity and hypertension, and the concept of "all things" encompasses the ideals of an active lifestyle and healthy aging. We advocate a Taoist way, "zero-one-all things," where "one" in this context refers to an inclusive and culturally diverse exercise training cocktail. The Tao guides us to illuminate an ancient way of overcoming physical inactivity-associated diseases in the present day.

Facilitators and barriers to real-life mobility in community-dwelling older adults: a narrative review of accelerometry- and global positioning system-based studies

Real-life mobility, also called "enacted" mobility, characterizes an individual's activity and participation in the community. Real-life mobility may be facilitated or hindered by a variety of factors, such as physical abilities, cognitive function, psychosocial aspects, and external environment characteristics. Advances in technology have allowed for objective quantification of real-life mobility using wearable sensors, specifically, accelerometry and global positioning systems (GPSs). In this review article, first, we summarize the common mobility measures extracted from accelerometry and GPS. Second, we summarize studies assessing the associations of facilitators and barriers influencing mobility of community-dwelling older adults with mobility measures from sensor technology. We found the most used accelerometry measures focus on the duration and intensity of activity in daily life. Gait quality measures, e.g., cadence, variability, and symmetry, are not usually included. GPS has been used to investigate mobility behavior, such as spatial and temporal measures of path traveled, location nodes traversed, and mode of transportation. Factors of note that facilitate/hinder community mobility were cognition and psychosocial influences. Fewer studies have included the influence of external environments, such as sidewalk quality, and socio-economic status in defining enacted mobility. Increasing our understanding of the facilitators and barriers to enacted mobility can inform wearable technology-enabled interventions targeted at delaying mobility-related disability and improving participation of older adults in the community.

Impact of different bilateral knee extension strengths on lower extremity performance

Despite the impact of leg muscle strength on lower extremity motor performance-including walking and sit-to-stand transfer-it remains difficult to predict the relationship between bilateral leg muscle strength and lower extremity performance. Therefore, this study was designed to predict lower extremity function through the differential modeling of logarithmic and linear regression, based on knee extension strength.The study included 121 individuals living in the same community. The bilateral strengths of the knee extensors were measured using a handheld dynamometer, and the Timed Up & Go test (TUG) performance time and 5-m minimum walking times were assessed to predict lower extremity motor functions. Bilateral normalized knee extension muscle strengths and lower extremity motor function scores, including walking or TUG performance times, were assessed on the logarithmic and linear models. The Akaike information criterion (AIC) was used to evaluate the coefficient compatibility between the logarithmic regression model and the linear regression model.The AIC value for the linear model was lower than that for the logarithmic model regarding the walking time. For walking time estimation in the linear model, the coefficient value of knee extension strength was larger on the strong than on the weak side; however, the AIC value for the logarithmic model was lower than that for the linear model regarding TUG performance time. In the logarithmic model's TUG performance time estimation, the coefficient value of knee extension strength was larger on the weak than on the strong side.In conclusion, our study demonstrated different models reflecting the relationship between both legs' strengths and lower extremity performance, including the walking and TUG performance times.

Mobility of Older Adults: Gait Quality Measures are associated with Life-Space Assessment Scores

BACKGROUND

The relation of gait quality to real-life mobility among older adults is poorly understood. This study examined the association between gait quality, consisting of step variability, smoothness, regularity, symmetry and gait speed with the Life-Space Assessment (LSA).

METHODS

In community-dwelling older adults (N=232, age 77.5±6.6, 65% females), gait quality was derived from: a) an instrumented walkway: gait speed, variability and walk-ratio; and b) accelerometer: signal variability, smoothness, regularity, symmetry, and time-frequency spatiotemporal variables during 6-minute walk. In addition to collecting LSA scores, cognitive functioning, walking-confidence, and falls were recorded. Spearman correlations (speed as covariate) and Random Forest Regression were used to assess associations between gait quality and LSA, and Gaussian-mixture modeling (GMM) was used to cluster participants.

RESULTS

Spearman correlations of ρp=0.11 (signal amplitude variability ML), ρp=0.15, ρp=-0.13 (symmetry AP-V, ML-AP), ρp=0.16 (power V) and ρ=0.26 (speed), all p<0.05 and marginally related, ρp=-0.12 (regularity V), ρp=0.11 (smoothness AP) and ρp=-0.11 (step-time variability), p<0.1 were obtained. The cross-validated Random Forest model indicated good fit LSA prediction error of 17.77; gait and cognition were greater contributors than age and gender. GMM indicated two clusters. Group-1(N=189) had better gait quality than Group-2(N=43): greater smoothness AP (2.94±0.75 vs 2.30±0.71); greater similarity AP-V (0.58±0.13 vs 0.40±0.19); lower regularity V (0.83±0.08 vs 0.87±0.10); greater power V (1.86±0.18 vs 0.97±1.84); greater speed (1.09±0.16 vs 1.00±0.16 m/s); lower step time CoV (3.70±1.09 vs 5.09±2.37) and better LSA (76±18 vs 67±18), padjusted<0.004.

CONCLUSIONS

Gait quality measures taken in the clinic are associated with real-life mobility in the community.

The association of objectively measured physical activity and sedentary behavior with skeletal muscle strength and muscle power in older adults: A systematic review and meta-analysis

BACKGROUND

Engaging in physical activity (PA) and avoiding sedentary behavior (SB) are important for healthy ageing with benefits including the mitigation of disability and mortality. Whether benefits extend to key determinants of disability and mortality, namely muscle strength and muscle power, is unclear.

AIMS

This systematic review aimed to describe the association of objective measures of PA and SB with measures of skeletal muscle strength and muscle power in community-dwelling older adults.

METHODS

Six databases were searched from their inception to June 21^st, 2020 for articles reporting associations between objectively measured PA and SB and upper body or lower body muscle strength or muscle power in community dwelling adults aged 60 years and older. An overview of associations was visualized by effect direction heat maps, standardized effect sizes were estimated with albatross plots and summarized in box plots. Articles reporting adjusted standardized regression coefficients (β) were included in meta-analyses.

RESULTS

A total of 112 articles were included representing 43,796 individuals (range: 21 to 3726 per article) with a mean or median age from 61.0 to 88.0 years (mean 56.4 % female). Higher PA measures and lower SB were associated with better upper body muscle strength (hand grip strength), upper body muscle power (arm curl), lower body muscle strength, and lower body muscle power (chair stand test). Median standardized effect sizes were consistently larger for measures of PA and SB with lower compared to upper body muscle strength and muscle power. The meta-analyses of adjusted β coefficients confirmed the associations between total PA (TPA), moderate-to-vigorous PA (MVPA) and light PA (LPA) with hand grip strength (β = 0.041, β = 0.057, and β = 0.070, respectively, all p ≤ 0.001), and TPA and MVPA with chair stand test (β = 0.199 and β = 0.211, respectively, all p ≤ 0.001).

CONCLUSIONS

Higher PA and lower SB are associated with greater skeletal muscle strength and muscle power, particularly with the chair stand test.

Using machine learning to investigate the relationship between domains of functioning and functional mobility in older adults

Previous studies have shown that functional mobility, along with other physical functions, decreases with advanced age. However, it is still unclear which domains of functioning (body structures, body functions, and activities) are most closely related to functional mobility. This study used machine learning classification to predict the rankings of Timed Up and Go tests based on the results of four assessments (soft lean mass, FEV1/FVC, knee extension torque, and one-leg standing time). We tested whether assessment results for each level could predict functional mobility assessments in older adults. Using support vector machines for machine learning classification, we verified that the four assessments of each level could classify functional mobility. Knee extension torque (from the body function domain) was the most closely related assessment. Naturally, the classification accuracy rate increased with a larger number of assessments as explanatory variables. However, knee extension torque remained the highest of all assessments. This extended to all combinations (of 2-3 assessments) that included knee extension torque. This suggests that resistance training may help protect individuals suffering from age-related declines in functional mobility.

Muscle Function Tests as Supportive Outcome Measures for Performance-Based and Self-Reported Physical Function in Patients With Knee Osteoarthritis: Exploratory Analysis of Baseline Data From a Randomized Trial

Holm, PM, Kemnitz, J, Bandholm, T, Wernbom, M, Schrøder, HM, and Skou, ST. Muscle function tests as supportive outcome measures for performance-based and self-reported physical function in patients with knee osteoarthritis: Exploratory analysis of baseline data from a randomized trial. J Strength Cond Res XX(X): 000-000, 2020-Uncertainty on the role of muscle function in relation to physical function in knee osteoarthritis (KOA) persists. This study aimed to assess the associations between muscle function and performance-based and self-reported physical function in patients with KOA. Physical function in 80 subjects with symptomatic and radiographic KOA was assessed using 40-m fast-paced walk, 30-second chair stand, 9-step stair climb tests, and the subscale activities of daily living from the Knee injury and Osteoarthritis Outcome Score (KOOS-ADL). Measurements of muscle function included leg extension (LE) power, knee extension (KE) torque, and estimated leg press one repetition maximum (LP RM). Associations were investigated using multivariable hierarchical linear regressions adjusted for age, sex, body mass index, self-reported physical activity, and thigh muscle lean area. Leg extension power was significantly associated with 40-m walk, stair climb, and 30-second chair stand, explaining 18, 8, and 3% of additional variance, respectively. Knee extension torque explained 13, 7, 17, and 7% of additional variance in the 40-m walk, stair climb, 30-second chair stand, and KOOS-ADL, respectively. Leg press one repetition maximum explained 11% of additional variance in the 30-second chair stand. In conclusion, LE power was the best explanatory variable for performance on the 40-m walk and stair climb tests, whereas KE torque best explained chair stand performance. Only KE torque was associated with KOOS-ADL. Our results highlight the importance of selecting supportive muscle function tests based on the specific physical function and suggest that other factors may be more important for certain physical function outcomes. Level of significance p < 0.05. Trial identifier: NCT03215602.

Effect of High-velocity Resistance Exercise on 24-h Blood Pressure in Hypertensive Older Women

This study investigated the acute post-exercise effect of high-velocity resistance exercise on ambulatory blood pressure in hypertensive older women. Fourteen volunteers (67.9±5.1 years) performed a high-velocity resistance exercise session (8 exercises using Thera-Band, 3 sets of 6 repetitions as fast as possible in the concentric phase with moderate intensity) and a control session, separated by a 7-10-day period. Ambulatory blood pressure was monitored following 12-h post-sessions and compared between conditions at 1 to 4-h, 5 to 8-h, and 9 to 12-h. Average 24-h ambulatory blood pressure, awake, asleep periods, and blood pressure load were also analyzed. There was a condition by time interaction for systolic ambulatory blood pressure over 12-h post-sessions (P=0.043). It was observed a lower systolic ambulatory blood pressure in the first 4-h period following the high-velocity resistance exercise session compared to the control session (-6.7 mmHg, 95% CI  - 11.6 to -1.8 mmHg; P=0.011). No changes were observed for diastolic ambulatory blood pressure over 12-h post-sessions as well as for the other variables analyzed (P>0.05). In summary, a single high-velocity resistance exercise session elicits a post-exercise antihypertensive effect and may be considered as a strategy to acutely improve blood pressure control in hypertensive older women.

Exploration of Habitual Walking Behavior and Home-Based Muscle Power Training in Individuals With Total Knee Arthroplasty

BACKGROUND

The purpose of this study was to investigate the effects of a home-based muscle power training program on muscle strength and power, functional performance, and physical activity behavior in individuals at least 6 months posttotal knee arthroplasty.

METHODS

Twelve men and women, mean age 63.9 (6.8) and 6 months to 2 years posttotal knee arthroplasty unilateral or bilateral), completed this study. Participants were randomly assigned to the home-based power training intervention or step-monitoring comparison group. Quadriceps muscle strength and power, 6-minute walk test, functional leg power, and habitual walking behavior (average daily steps, minutes per week of moderate to vigorous physical activity) were assessed before and after intervention and then compared between and within groups.

RESULTS

The authors found no significant differences between the groups on amount of change in any of the outcomes, but mixed results on differences within each of the groups on the outcome measures.

CONCLUSION

There were no differences between the groups for amount of change on the outcome measures the authors selected. Although within group differences varied slightly for each group, it was not enough to justify the more expensive home-based power training over the simpler step-monitoring intervention.

Physiological and Functional Alterations after Spaceflight and Bed Rest

Supplemental digital content is available in the text.

Introduction

Exposure to microgravity causes alterations in multiple physiological systems, potentially impacting the ability of astronauts to perform critical mission tasks. The goal of this study was to determine the effects of spaceflight on functional task performance and to identify the key physiological factors contributing to their deficits.

Methods

A test battery comprised of seven functional tests and 15 physiological measures was used to investigate the sensorimotor, cardiovascular, and neuromuscular adaptations to spaceflight. Astronauts were tested before and after 6-month spaceflights. Subjects were also tested before and after 70 d of 6° head-down bed rest, a spaceflight analog, to examine the role of axial body unloading on the spaceflight results. These subjects included control and exercise groups to examine the effects of exercise during bed rest.

Results

Spaceflight subjects showed the greatest decrement in performance during functional tasks that required the greatest demand for dynamic control of postural equilibrium which was paralleled by similar decrements in sensorimotor tests that assessed postural and dynamic gait control. Other changes included reduced lower limb muscle performance and increased HR to maintain blood pressure. Exercise performed during bed rest prevented detrimental change in neuromuscular and cardiovascular function; however, both bed rest groups experienced functional and balance deficits similar to spaceflight subjects.

Conclusion

Bed rest data indicate that body support unloading experienced during spaceflight contributes to postflight postural control dysfunction. Further, the bed rest results in the exercise group of subjects confirm that resistance and aerobic exercises performed during spaceflight can play an integral role in maintaining neuromuscular and cardiovascular functions, which can help in reducing decrements in functional performance. These results indicate that a countermeasure to mitigate postflight postural control dysfunction is required to maintain functional performance.

Relationship Between Strength Parameters and Functional Performance Tests in Patients With Severe Knee Osteoarthritis

BACKGROUND

Decreased leg muscle strength is a major determinant of reduced function in patients with knee osteoarthritis (OA). The identification of a strength parameter that is best correlated with functional performance is important for monitoring rehabilitation results.

OBJECTIVE

To determine which muscle strength measurements show the highest correlation with functional capacity in patients with severe knee OA shortly before total knee arthroplasty (TKA).

DESIGN

Cross-sectional exploratory study.

SETTING

Outpatient rehabilitation department at a university teaching hospital.

PATIENTS

The sample included 75 patients (51 female) scheduled for primary TKA, recruited through multistage sampling.

METHODS OR INTERVENTIONS

Independent variables were peak isometric, isokinetic concentric, and eccentric leg extensor strength measured on the leg press, as well as peak isometric knee extensor strength measured on the strength chair. Two multiple regression analyses were performed, one including all strength measures and the other including all of the strength ratios. Pearson correlation coefficients were calculated between the strength measures and functional test scores.

MAIN OUTCOME MEASUREMENTS

Dependent variables were the Timed Up and Go Test (TUG) and the Stair Test (ST).

RESULTS

The regression analysis including all strength measures could explain 11.9% of the variance of the TUG (P = .068, not significant [NS]) and 21.5% of the variance of the ST (P = .009, significant). The regression model for the strength ratios explained 11.8% of the variance of the TUG (P = .090, NS) and 6.3% of the ST (P = .217, NS).

CONCLUSIONS

Although univariate analysis confirmed significant correlations between strength measurements and functional tests, multiple regression analysis revealed a higher predictive value for the ST than for the TUG. The use of both muscle strength tests and performance-based function tests is advisable to evaluate functional impairments of patients with knee OA.

LEVEL OF EVIDENCE

III.

Changes in Intensity and Duration of Walking among Older Adults from In-Patient Geriatric Rehabilitation to Home

Purpose: We compared walking in hospital and on discharge from in-patient geriatric rehabilitation. Method: Participants included 28 adults (22 women) with a mean age of 85.4 (SD 6.8) years, ambulating independently with planned discharge to the community. Steps per day, short and long walking bouts, and cadence (steps per minute) were measured using an ActiGraph GT3X+ activity monitor (5 d in hospital, 5 d at home). Results: Steps per day did not differ between hospital and home (median difference=401; 95% CI: -364, 1,215; p=0.10). Long walking bouts (≥5 min) were infrequent in both locations (1/d) but lasted longer in hospital. Short walking bouts (≥15 s) were more frequent and shorter at home. Daily peak 1-minute cadence and peak 30-minute cadence were greater in hospital. Conclusions: Older adults in geriatric rehabilitation take longer walks and walk at faster paces in hospital, and they engage in more frequent, shorter walks at home. Although further research is needed, older adults would benefit from the opportunity to walk at different paces and different distances on discharge. Outpatient rehabilitation or other community-based programmes and initiatives may provide these experiences and appropriate environments to enable individuals to maintain mobility and independent functioning in the long term.

Objective measures of physical activity in patients with chronic unilateral vestibular hypofunction, and its relationship to handicap, anxiety and postural stability

OBJECTIVE

Dizziness is one of the most common symptoms in the general population. Patients with dizziness experience balance problems and anxiety, which can lead to decreased physical activity levels and participation in their daily activities. Moreover, recovery of vestibular function from vestibular injury requires physical activity. Although there are reports that decreased physical activity is associated with handicap, anxiety, postural instability and reduced recovery of vestibular function in patients with chronic dizziness, these data were collected by self-report questionnaires. Therefore, the objective data of physical activity and the relationships between physical activity, handicap, anxiety and postural stability in patients with chronic dizziness are not clear. The purpose of this research was to objectively measure the physical activity of patients with chronic dizziness in daily living as well as handicap, anxiety and postural stability compared to healthy adults. Additionally, we aimed to investigate the relationships between physical activity, handicap, anxiety and postural stability in patients with chronic dizziness.

METHODS

Twenty-eight patients with chronic dizziness of more than 3 months caused by unilateral vestibular hypofunction (patient group) and twenty-eight age-matched community dwelling healthy adults (healthy group) participated in this study. The amount of physical activity including time of sedentary behavior, light physical activity, moderate to vigorous physical activity and total physical activity using tri-axial accelerometer, self-perceived handicap and anxiety using questionnaires, and postural stability were measured using computerized dynamic posturography.

RESULTS

The results showed worse handicap, anxiety and postural stability in the patient group compared to the healthy group. Objective measures of physical activity revealed that the patient group had significantly longer time of sedentary behavior, shorter time of light physical activity, and shorter time of total physical activity compared to the healthy group; however, time of moderate to vigorous physical activity was not significantly different between groups. Moreover, there were correlations between physical activity and postural stability in the patient group, while there were no correlations between physical activity, handicap or anxiety in the patient group.

CONCLUSION

These results suggest that objectively measured physical activity of the patients with chronic unilateral vestibular hypofunction is lower compared to the healthy adults, and less active patients showed decreased postural stability. However, the details of physical activity and causal effect between physical activity and postural stability were not clear and further investigation is needed.

The use of wearable devices for walking and running gait analysis outside of the lab: A systematic review

BACKGROUND

Quantitative gait analysis is essential for evaluating walking and running patterns for markers of pathology, injury, or other gait characteristics. It is expected that the portability, affordability, and applicability of wearable devices to many different populations will have contributed advancements in understanding the real-world gait patterns of walkers and runners. Therefore, the purpose of this systematic review was to identify how wearable devices are being used for gait analysis in out-of-lab settings.

METHODS

A systematic search was conducted in the following scientific databases: PubMed, Medline, CINAHL, EMBASE, and SportDiscus. Each of the included articles was assessed using a custom quality assessment. Information was extracted from each included article regarding the participants, protocol, sensor(s), and analysis.

RESULTS

A total of 61 articles were reviewed: 47 involved gait analysis during walking, 13 involved gait analysis during running, and one involved both walking and running. Most studies performed adequately on measures of reporting, and external and internal validity, but did not provide a sufficient description of power. Small, unobtrusive wearable devices have been used in retrospective studies, producing unique measures of gait quality. Walking, but not running, studies have begun to use wearable devices for gait analysis among large numbers of participants in their natural environment.

CONCLUSIONS

Despite the advantages provided by the portability and accessibility of wearable devices, more studies monitoring gait over long periods of time, among large numbers of participants, and in natural walking and running environments are needed to analyze real-world gait patterns, and would facilitate prospective, subject-specific, and subgroup investigations. The development of wearables-specific metrics for gait analysis provide insights regarding the quality of gait that cannot be determined using traditional components of in-lab gait analyses. However, guidelines for the usability of wearable devices and the validity of wearables-based measurements of gait quality need to be established.

Effects of Walking on Coronary Heart Disease in Elderly Men with Diabetes

Previous studies have shown that walking is associated with increased longevity and a reduced risk of cardiovascular and age-related diseases. Whether walking benefits individuals with diabetes who are at high risk of coronary heart disease (CHD) remains to be determined. The objective of this study is to examine the association between walking and risk of CHD among elderly men with and without diabetes. Walking data was assessed in 2732 men aged 71 to 93 years participating in the Honolulu Heart Program from 1991-1993. Study participants were initially without disabilities and free of prevalent CHD. Men were then followed for incident CHD for up to 7 years. For men with diabetes who walked <0.25 miles/day, the age-adjusted incidence of CHD was significantly higher than in men without diabetes (27.1 vs. 12.7/1000 person years, p = 0.026). In contrast when distance walked was >1.5 miles/day, incidence of CHD was similar in men with and without diabetes (12.2 vs. 9.1/1000 person-years, p = 0.46). While risk of CHD declined significantly with increasing walking distance in men with diabetes after age and risk factor adjustment (p = 0.043, p = 0.025), associations in those without diabetes were weaker (p = 0.070, p = 0.10). These findings suggest that among elderly men with diabetes who are capable of physical activity, walking reduces CHD risk to levels similar to when diabetes is absent. Walking is an easy, safe and accessible form of physical activity that may have marked health benefits for elderly men with diabetes.

Knee Extensor Rate of Torque Development Before and After Arthroscopic Partial Meniscectomy, With Analysis of Neuromuscular Mechanisms

Study Design Descriptive, prospective single-cohort longitudinal study. Background Though rapid torque development is essential in activities of daily living and sports, it hasn't been specifically tested by most physical therapists or incorporated into rehabilitation programs until late in the treatment process. Little evidence is available on quadriceps torque development capacity before and after arthroscopic knee surgery. Objectives To study knee extensor rate of torque development, contributing mechanisms, and associations with strength and patient-reported outcomes before and during the first 6 weeks after arthroscopic partial meniscectomy. Methods Twenty subjects (mean ± SD age, 42.3 ± 13.7 years; body mass index, 26.6 ± 3.1 kg/m²) were tested before surgery, and at 2 and 5 weeks after surgery. Quadriceps muscle volume, strength, activation, rate of torque development, and patient-reported outcomes were evaluated across the study period. Results Significant side-to-side differences in quadriceps strength and voluntary rate of torque development were observed at each time point (P<.05). Changes in muscle activity were associated with changes in rapid torque development capacity. Side-to-side rate of torque development deficits after surgery were associated with lower patient-reported outcomes scores. Conclusion Diminished rapid torque development capacity is common in arthroscopic meniscal debridement patients. This reduced capacity is associated with an inability to quickly recruit and drive the quadriceps muscles (neural mechanisms) and not muscle atrophy or other peripheral factors tested. Patient-reported outcomes are associated with quadriceps rate of torque development, but not strength or muscle size. Rapid torque development warrants greater attention in rehabilitation. J Orthop Sports Phys Ther 2017;47(12):945-956. Epub 9 Oct 2017. doi:10.2519/jospt.2017.7310.

The contribution of leg press and knee extension strength and power to physical function in people with knee osteoarthritis: A cross-sectional study

The purposes of this study were to 1) determine the additional contributions of leg press and knee extensor power, over and above that of strength, to the performance of physical function tasks in people with knee osteoarthritis, and 2) compare the ability of bilateral leg press to unilateral knee extensor strength and power to predict functional task performance.

METHODS

A cross-sectional, exploratory study of 40 individuals with tibiofemoral knee osteoarthritis resulting in moderate impairments in physical function was conducted. Physical function (Get-up and Go, timed stair climb and descent, and five time chair rise) and muscle performance (leg press and knee extension strength and power) were assessed.

RESULTS

After controlling for covariates and strength, leg press, but not knee extensor, power explained additional variance in physical function (11% and 21%). Conversely, adding strength to regression models including covariates and power did not consistently improve the prediction of physical function. Additionally, leg press power consistently explained more variance in physical function (44 to 57%) than involved (24 to 34%) or uninvolved (28 to 48%) knee extension power.

CONCLUSIONS

Leg press power may be a more functionally relevant measure of muscle performance than knee extension strength in this population. Future studies should investigate the effectiveness of interventions specifically designed to improve leg press power in people with knee osteoarthritis.

Physical Activity Intervention Effects on Physical Function Among Community-Dwelling Older Adults: A Systematic Review and Meta-Analysis

The purpose of this systematic review and meta-analysis was to determine the effects of supervised resistance and/or aerobic training physical activity interventions on performance-based measures of physical functioning among community-dwelling older adults, and to identify factors impacting intervention effectiveness. Diverse search strategies were used to identify eligible studies. Standardized mean difference effect sizes (d, ES) were synthesized using a random effects model. Moderator analyses were conducted using subgroup analyses and meta-regression. Twenty-eight studies were included. Moderator analyses were limited by inconsistent reporting of sample and intervention characteristics. The overall mean ES was 0.45 (k = 38, p ≤ .01), representing a clinically meaningful reduction of 0.92 s in the Timed Up and Go for treatment versus control. More minutes per week (p < .01) and longer intervention session duration (p < .01) were associated with larger effects. Interventions were especially effective among frail participants (d = 1.09). Future research should clearly describe sample and intervention characteristics and incorporate frail populations.

Handgrip strength, quadriceps muscle power, and optimal shortening velocity roles in maintaining functional abilities in older adults living in a long-term care home: a 1-year follow-up study

Purpose

To assess the relative role of handgrip strength (HGS), quadriceps muscle power (P_max), and optimal shortening velocity (υ_opt) in maintaining functional abilities (FAs) in older adults living in a long-term care home over a 1-year follow-up.

Subjects and methods

Forty-one inactive older institutionalized adults aged 69.8±9.0 years participated in this study. HGS, P_max, υ_opt, cognitive function using the Mini-Mental State Examination, depressive symptoms using the Geriatric Depression Scale, nutritional status using the Mini Nutritional Assessment (MNA), and physical activity (PA) using the Seven-Day Physical Activity Recall Questionnaire were assessed at baseline and at 1-year follow-up. FAs were assessed with activities of daily living (ADL), instrumental ADL, and Timed Up & Go test.

Results

Both at baseline and at follow-up, FAs were related to age, HGS, P_max/kg, υ_opt, MNA, and PA. These associations were generally similar in both sexes. As revealed in multiple regression analysis, υ_opt was the strongest predictor of FA, followed by P_max/kg, PA, and MNA. FA deteriorated after 1 year as measured by ADL and Timed Up & Go test. P_max and υ_opt, but not HGS, also decreased significantly after 1 year. Nevertheless, 1-year changes in FAs were not related to changes in HGS, P_max, υ_opt, or PA.

Conclusion

The 1-year period of physical inactivity among older institutionalized adults was found to have a negative effect on their FAs, P_max, and υ_opt. The present study demonstrates that P_max and, especially, υ_opt correlated with FAs of older adults more than HGS, both at baseline and at follow-up. Despite this, 1-year natural fluctuations of PA, P_max, and υ_opt are not significant enough to influence FAs in inactive institutionalized older adults.

Parameters of gait among community-dwelling older adults

BACKGROUND

Functional fitness is the ability of an older adult to perform activities of daily living. Stair-climb power is a well-documented marker of functional fitness among older adults. Gait velocity and parameters of gait are related to functional fitness but have been understudied to date.

PURPOSE

The purpose of this observational study was to determine differences in parameters of gait between high- and low-functioning older adults.

METHODS

Twenty high-functioning older adults, mean age (SD)=71.6 (5.6), volunteered for the cross-sectional observational study. Functional fitness was determined by a stair-climb performance test. Parameters of gait included velocity, step length, swing and stance phase, double support time, ground reaction forces, impulse, and propulsion during habitual walking. Analysis of variance was performed to determine differences in the dependent variables between groups.

RESULTS

Individuals with high levels of functional fitness walked 13.1% faster than the lower-functioning group (P=.01). No significant differences (P>.05) were detected for any other measure; however, all gait parameters were more favorable in the higher-functioning group.

CONCLUSION

Functional fitness is imperative for older adults as declines could hinder mobility. Thus, earlier detection of declines in gait parameters may reduce the risk of falling. The results suggest that gait velocity was slower among older adults with lower levels of functional fitness.

Power training in patients with knee osteoarthritis: a pilot study on feasibility and efficacy

PURPOSE

To explore the feasibility and efficacy of using a power training exercise programme for the quadriceps femoris (QF) in elderly women with knee osteoarthritis (OA).

METHOD

A one-group quasi-experimental design with pre- and post-intervention measurements was conducted on 17 older adult women with knee OA pain. A bilateral QF exercise programme (24 sessions over 8 weeks) consisting of 3 series of 10 repetitions of flexion-extension as fast as possible at 40% of their one-repetition maximum (1RM) was performed in an outpatient physiotherapy clinic. The primary outcome measures were the knee function and associated problems using the Knee injury Osteoarthritis Outcome Score (KOOS) questionnaire and the weekly mean pain score from pain diaries using a visual analogue scale (VAS). QF strength (QFS), power (QFP) and work (QFW) were measured with an isokinetic dynamometer as secondary outcomes.

RESULTS

Significant improvements (p<0.05) were noted on the five categories of the KOOS. Significant decrease (p<0.01) was noted in pain intensity on VAS. QFP and QFW increased significantly on both sides (p<0.05). Exercise compliance was 99.5% for 16 participants.

CONCLUSIONS

A short power-training exercise programme is a feasible training modality for patients with knee OA, and significant functional improvements can be achieved. Further studies must be conducted to better understand the effects of the programme parameters and the generalizability of the findings.

Association between physical activity levels and physiological factors underlying mobility in young, middle-aged and older individuals living in a city district

Maintaining adequate levels of physical activity is known to preserve health status and functional independence as individuals grow older. However, the relationship between determinants of physical activity (volume and intensity) and physiological factors underlying mobility (cardio-respiratory fitness, neuromuscular function and functional abilities) is still unclear. The aim of this study was to investigate the association between objectively quantified physical activity and a spectrum of physiological factors underlying mobility in young, middle-aged and older individuals living in a city district. Experiments were carried out on 24 young (28 ± 2 years), 24 middle-aged (48 ± 2 years) and 24 older (70 ± 3 years) gender-matched volunteers. Physical activity was monitored by a wearable activity monitor to quantify volume and intensity of overall physical activity and selected habitual activities over 24 hours. Ventilatory threshold was assessed during an incremental cycling test. Torque, muscle fiber conduction velocity and agonist-antagonist coactivation were measured during maximal voluntary contraction of knee extensors and flexors. Ground reaction forces were measured during sit-to-stand and counter-movement jump. K-means cluster analysis was used to classify the participants' physical activity levels based on parameters of volume and intensity. Two clusters of physical activity volume (i.e., high and low volume) and three clusters of physical activity intensity (i.e. high, medium and low intensity) were identified in all participants. Cardio-respiratory fitness was associated with volume of overall physical activity as well as lying, sitting, standing, walking and stair climbing. On the other hand, neuromuscular function and functional abilities showed a significant association with intensity of overall physical activity as well as postural transition, walking and stair climbing. As a practical application, the relative role played by volume and intensity of overall physical activity and selected habitual activities should be taken into account in the design of preventative training interventions to preserve mobility as individuals grow older.

Association between Sarcopenia, Bone Density, and Health-Related Quality of Life in Korean Men

Background

Sarcopenia is the loss of muscle mass leading to decreased muscle strength, physical disability, and increased mortality. The genesis of both sarcopenia and osteoporosis is multifactorial, and several factors that play a role in osteoporosis are thought to contribute to sarcopenia. This study evaluated the association between sarcopenia and bone density and health-related quality of life in Korean men.

Methods

We used the data of 1,397 men over 50 years of age from the 2009 Korean National Health and Nutrition Examination Survey. Sarcopenia was defined as the appendicular skeletal muscle mass divided by height² (kg/m²) < 2 standard deviations below the sex-specific mean for young adults. Health-related quality of life was measured by the EuroQol-5 dimension (EQ-5D) instrument. Logistic regression analysis was performed to evaluate the relationship between sarcopenia, bone density, and health-related quality of life.

Results

The T-score of the lumbar spine, total femur, and femur neck in bone mineral density in subjects with sarcopenia were lower than those in subjects without sarcopenia. The score of the EQ-5D index was significantly lower and the rate of having problems with individual components of health-related quality of life was higher in the sarcopenic group. After adjustment for age and body mass index, the odds ratios (ORs) (95% confidence interval [CI]) for sarcopenia were 2.06 (1.07-3.96) in osteopenic subjects and 3.49 (1.52-8.02) in osteoporotic subjects, respectively. After adjustment, the total score of the EQ-5D index was significantly lower in the sarcopenic subjects. The ORs (95% CI) for having problems of mobility and usual activity of the EQ-5D descriptive system were 1.70 (1.02-2.84) and 1.90 (1.09-3.31), respectively.

Conclusion

Sarcopenia was associated with decreased bone mineral density in Korean men. In addition, sarcopenia was related to poor quality of life, especially with regard to mobility and usual activity. Greater attention to and evaluation for sarcopenia are needed in subjects showing low bone mineral density to prevent and manage poor quality of life.

Quantifying physical activity levels of survivors of intensive care: a prospective observational study

BACKGROUND

Promotion of increased physical activity is advocated for survivors of an intensive care unit (ICU) admission to improve physical function and health-related quality of life.

OBJECTIVE

The primary aims of this study were: (1) to measure free-living physical activity levels and (2) to correlate the measurements with scores on a self-reported activity questionnaire. A secondary aim was to explore factors associated with physical activity levels.

DESIGN

This was a prospective cohort study.

METHODS

Nested within a larger randomized controlled trial, participants were block randomized to measure free-living physical activity levels. Included participants wore an accelerometer for 7 days during waking hours at 2 months after ICU discharge. At completion of the 7 days of monitoring, participants were interviewed using the Physical Activity Scale for the Elderly (PASE) questionnaire. Factors associated with physical activity were explored using regression analysis.

RESULTS

The ICU survivors (median age=59 years, interquartile range=49-66; mean Acute Physiologic Chronic Health Evaluation [APACHE II] score=18, interquartile range=16-21) were inactive when quantitatively measured at 2 months after hospital discharge. Participants spent an average of 90% of the time inactive and only 3% of the time walking. Only 37% of the sample spent 30 minutes or more per day in the locomotion category (more than 20 steps in a row). Activity reported using the PASE questionnaire was lower than that reported in adults who were healthy. The PASE scores correlated only fairly with activity measured by steps per day. The presence of comorbidities explained one third of the variance in physical activity levels.

LIMITATIONS

Accelerometer overreading, patient heterogeneity, selection bias, and sample size not reached were limitations of the study.

CONCLUSIONS

Survivors of an ICU admission greater than 5 days demonstrated high levels of inactivity for prolonged periods at 2 months after ICU discharge, and the majority did not meet international recommendations regarding physical activity. Comorbidity appears to be a promising factor associated with activity levels.

Influence of muscle strength to weight ratio on functional task performance

Existing models of muscle deconditioning such as bed rest are expensive and time-consuming. We propose a new model utilizing a weighted suit to manipulate muscle strength, power, or endurance relative to body weight. The aims of the study were to determine as to which muscle measures best predict functional task performance and to determine muscle performance thresholds below which task performance is impaired. Twenty subjects performed seven occupational astronaut tasks (supine and upright seat egress and walk, rise from fall, hatch opening, ladder climb, object carry, and construction board activity), while wearing a suit weighted with 0-120 % of body weight. Models of the relationship between muscle function/body weight and task completion time were developed using fractional polynomial regression and verified with pre- and post-flight astronaut performance data. Spline regression was used to identify muscle function thresholds for each task. Upright seat egress and walk was the most difficult task according to the spline regression analysis thresholds. Thresholds normalized to body weight were 17.8 N/kg for leg press isometric force, 17.6 W/kg for leg press power, 78.8 J/kg for leg press work, 5.9 N/kg isometric knee extension and 1.9 Nm/kg isokinetic knee extension torque. Leg press maximal isometric force/body weight was the most reliable measure for modeling performance of ambulatory tasks. Laboratory-based manipulation of relative strength has promise as an analog for spaceflight-induced loss of muscle function. Muscle performance values normalized to body weight can be used to predict occupational task performance and to establish relevant strength thresholds.

Can an accelerometer-based monitor be used to accurately assess physical activity in a population of survivors of critical illness?

Purpose:

To investigate the validity and reliability of the Activity Monitoring Pod (AMP331) to record gait parameters in healthy young adults (YA) and intensive care unit inpatients (ICU).

Methods:

YA (N=15) completed a series of over-ground walks. Another 15 YA completed a series of treadmill walks. The ICU group (N=20) completed a series of over-ground walks with repeat trials. Gait parameters were recorded simultaneously by the AMP 331 and the Vicon (YA) and the AMP 331, direct observation and a stopwatch (ICU).

Results:

For the YA over-ground, no significant differences were found between the measures recorded by the systems. For the YA treadmill, 43% of the measures differed (P < .05). For the ICU group, the AMP331 underestimated distance and speed by 3m and 25cm/s respectively. Reliability measures (ICU group) for distance (ICC 0.99, 95%CI 0.98 – 0.99) and step count (ICC 0.99, 95%CI 0.99 – 1.00) were excellent.

Conclusions:

The AMP 331 is a valid instrument for recording basic gait parameters for over-ground walking in healthy YA and ICU survivors.

How to assess functional status: a new muscle quality index

Aging is associated with decreases in muscle mass, muscle strength and muscle power, with muscle strength declining at a higher rate than muscle mass, but at a lower rate than muscle power. This progressive mismatch suggests a deterioration of muscle "quality" that may lead to functional incapacities. Although it may be difficult to synthesize the concept of muscle quality, the aim of the present paper was to propose a clinical definition of muscle quality in regard to the functional status. Accordingly, the muscle strength or muscle power per unit of muscle mass ratios appear to be clinically relevant markers of muscle quality. Several mechanisms susceptible to influence these ratios have been described, among which age, gender, sex hormones, obesity, physical activity and fibrosis. Various methods to assess muscle quality in both the clinical and research fields have also been listed, with a particular interest for the tests used to measure muscle power. Finally, we proposed a clinical screening tool to detect individuals at risk of functional incapacities. Briefly, the muscle quality score is based on handgrip strength assessment by hand dynamometer, muscle mass measurement by bioelectrical analysis, and leg muscle power estimation using a chair stand test.

Relations of meeting national public health recommendations for muscular strengthening activities with strength, body composition, and obesity: the Women's Injury Study

OBJECTIVES

We examined the relations of meeting or not meeting the 2008 Physical Activity Guidelines for Americans recommendations for muscular strengthening activities with percentage of body fat, body mass index (BMI; defined as weight in kilograms divided by height in meters, squared), muscular strength, and obesity classification in women.

METHODS

We analyzed data on 918 women aged 20 to 83 years in the Women's Injury Study from 2007 to 2009. A baseline orthopedic examination included measurement of height, body weight, skinfolds, and muscle strength.

RESULTS

Women who met muscle strengthening activity recommendations had significantly lower BMI and percentage of body fat and higher muscle strength. Women not meeting those recommendations were more likely to be obese (BMI ≥ 30) compared with women who met the recommendations after we adjusted for age, race, and aerobic physical activity (odds ratio = 2.28; 95% confidence interval = 1.61, 3.23).

CONCLUSIONS

There was a small but significant positive association between meeting muscle strengthening activity recommendations and muscular strength, a moderate inverse association with body fat percentage, and a strong inverse association with obesity classification, providing preliminary support for the muscle strengthening activity recommendation for women.

Physical activity, exercise, and sarcopenia - future challenges

BACKGROUND

Numerous studies have demonstrated that the etiology of sarcopenia is multi-causal and very complex process. The degradation of muscle mass leads to a loss of strength, later on to a decreased functional status, impaired mobility, a higher risk of falls, and eventually an increased risk of mortality. Present guidelines state that physical inactivity or a decreased physical activity level is a part of the underlying mechanisms of sarcopenia and therefore physical activity can be seen as an important factor to reverse or modify the development of sarcopenia.

TOPIC

Results in the area of physical activity and aging have not always been homogeneous. The inconsistent findings in this research area are related to the different understanding of terms and underlying constructs along with different population, type of intervention, or measurement methods. These aspects will be discussed in the paper. With regard to the formulated future role of physical activity this article will discuss in addition different barriers and challenges in the prevention and treatment of sarcopenia. A multitude of studies shows that structured exercise programs including progressive resistance or power training have positive effects on sarcopenia and sarcopenia-related outcomes but less or inconclusive information is available for the transfer to functional outcomes.

CONCLUSIONS

Both physical activities and exercise have shown to decrease risk of sarcopenia and onset of functional limitations in older persons. Unfortunately the cohort of older persons is the one with the highest percentage of individuals classified as inactive or sedentary. Therefore motivating older persons to increase their physical activity level as well as providing safe access to exercise programs seems to be a mandatory task.

Functional muscle power testing in young, middle-aged, and community-dwelling nonfrail and prefrail older adults

OBJECTIVE

To evaluate the stair climb (SC) and sit-to-stand (STS) transfer test for functional power assessment in young, middle-aged, and community-dwelling nonfrail and prefrail older adults.

DESIGN

Cross-sectional study.

SETTING

Sport science institute providing health-related exercise programs for older people.

PARTICIPANTS

Participants (N=60; age, 22-81y) were divided into groups of young (n=15; 20-30y), middle-aged (n=16; 40-60y), nonfrail older (n=16; >65y), and prefrail older adults (n=13; >65y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

SC and STS transfer power were measured on 2 separate occasions.

RESULTS

Age and height correlated positively (P<.001) with both power measures. Multiple linear regression analysis showed that 67.9% (R(2)) of the variance in SC power and 31.3% (R(2)) of the variance in STS transfer power can be attributed to age and height. Significant age-related subgroup differences were found for SC power (P=.001). Nonfrail and prefrail older adults differed significantly in both power measures (P<.001).

CONCLUSIONS

The findings indicate that SC and STS transfer power are sensitive enough to distinguish between nonfrailty and prefrailty. This suggests that both tests are relevant clinical measures in older people.

Personal factors, perceived environment, and objectively measured walking in old age

This study examined the associations between walking behavior and the perceived environment and personal factors among older adults. Sixty participants age 65 yr or older (mean 77 +/- 7.27, range 65-92) wore pedometers for 3 consecutive days. Perceived environment was assessed using the Neighborhood Environment Walkability Scale (abbreviated version). Physical function was measured using the timed chair-stands test. The mean number of steps per day was 5,289 steps (SD = 4,029). Regression analyses showed a significant association between personal factors, including physical function (relative rate = 1.05, p < .01) and income (RR = 1.43, p < .05) and the average daily number of steps taken. In terms of perceived environment, only access to services was significantly related to walking at the univariate level, an association that remained marginally significant when controlling for personal characteristics. These results suggest that among this sample of older adults, walking behavior was more related to personal and intrinsic physical capabilities than to the perceived environment.

Regional muscle and whole-body composition factors related to mobility in older individuals: a review

PURPOSE

To describe previously reported locomotor muscle and whole-body composition factors related to mobility in older individuals.

METHODS

A narrative review of the literature, including a combination of search terms related to muscle and whole-body composition factors and to mobility in older individuals, was carried out. Statistical measures of association and risk were consolidated to summarize the common effects between studies.

RESULTS

Fifty-three studies were reviewed. Muscle and whole-body factors accounted for a substantial amount of the variability in walking speed, with coefficients of determination ranging from 0.30 to 0.47. Muscle power consistently accounted for a greater percentage of the variance in mobility than did strength. Risks associated with high fat mass presented a minimum odds ratio (OR) of 0.70 and a maximum OR of 4.07, while the minimum and maximum ORs associated with low lean mass were 0.87 and 2.30 respectively. Whole-body and regional fat deposits accounted for significant amounts of the variance in mobility.

CONCLUSION

Muscle power accounts for a greater amount of the variance in the level of mobility in older individuals than does muscle strength. Whole-body fat accounts for a greater amount of the variance in level of mobility than does whole-body lean tissue. Fat stored within muscle also appears to increase the risk of a mobility limitation in older individuals.