Lower-Extremity Kinetic Response to Weighted-Vest Resistance during Stepping Exercise in Older Adults

2004 ◽  
Vol 20 (3) ◽  
pp. 260-274 ◽  
Author(s):  
George J. Salem ◽  
Sean P. Flanagan ◽  
Man-Ying Wang ◽  
Joo-Eun Song ◽  
Stanley P. Azen ◽  
...  

Stepping activities when wearing a weighted vest may enhance physical function in older persons. Using 3 weighted-vest resistance dosages, this study characterized the lower-extremity joint biomechanics associated with stepping activities in elders. Twenty healthy community-dwelling older adults, ages 74.5 ± 4.5 yrs, performed 3 trials of forward step-up and lateral step-up exercises while wearing a weighted vest which added 0% body weight (BW), 5% BW, or 10% BW. They performed these activities on a force platform while instrumented for biomechanical analysis. Repeated-measures ANOVA was used to evaluate the differences in ankle, knee, and hip maximum joint angles, peak net joint moments, joint powers, and impulses among both steping activities and the 3 loading conditions. Findings indicated that the 5% BW vest increased the kinetic output associated with the exercise activities at all three lower-extremity joints. These increases ranged from 5.9% for peak hip power to 12.5% for knee extensor impulse. The application of an additional 5% BW resistance did not affect peak joint moments or powers, but it did increase the joint impulses by 4–11%. Comparisons between exercise activities, across the 3 loading conditions, indicated that forward stepping preferentially targeted the hip extensors while lateral stepping targeted the plantar flexors; both activities equally targeted the knee extensors. Weighted-vest loads of 5% and 10% BW substantially increased the mechanical demand on the knee extensors, hip extensors (forward stepping), and ankle plantar flexors (lateral stepping).

2000 ◽  
Vol 8 (3) ◽  
pp. 214-227 ◽  
Author(s):  
L. Jerome Brandon ◽  
Lisa W. Boyette ◽  
Deborah A. Gaasch ◽  
Adrienne Lloyd

This study evaluated the effects of a 4-month lower extremity strength-training program on mobility in older adults. Eighty-five older adults (43 experimental, ES, and 42 comparison, CS) with a mean age of 72.3 years served as participants. The ES strength-trained plantar flexors (PF), knee flexors (KF), and knee extensors (KE) 1 hr/day, 3 days a week for 4 months. Both the ES and CS were evaluated for PF, KF, and KE strength (1 RM) and the time required to complete floor rise, chair rise, 50-ft walk, and walking up and down stairs before and after the training intervention. The ES increased (p < .05) both absolute (51.9%) and relative strength (1 RM/body weight, 52.4%) after training. Only chair-rise and floor-rise tasks improved significantly after training. Baseline and posttraining mobility tasks predicted from 1 RMs had low to moderate R values. These results suggest that strength is necessary for mobility, but increasing strength above baseline provides only marginal improvement in mobility for reasonably fit older adults.


2012 ◽  
Vol 92 (9) ◽  
pp. 1148-1159 ◽  
Author(s):  
Moshe Marko ◽  
Christopher G. Neville ◽  
Mark A. Prince ◽  
Lori L. Ploutz-Snyder

BackgroundMany apparently independent older adults modify daily tasks. Task modifications strongly predict future mobility disability. Clinically intuitive, easily measured “biomarkers” associated with task modifications would offer quantifiable treatment targets for prevention of age-related functional limitations.ObjectiveThe objective of the study was to examine lower-extremity muscle strength deficits and functionally relevant cutoff points associated with daily task modifications in community dwelling older adults living independently.DesignThis was a cross-sectional observational study.MethodsFifty-three participants (mean age=76.4 years, SD=5.2) were tested for task modifications and leg strength. Task modifications were assessed using a previously described tool (summary task modification score). Twenty-six of the participants were classified as task modifiers (TM group), and 27 participants were classified as non–task modifiers (NTM group). A net antigravity leg force in the sagittal plane (NETforce) was calculated by summing the normalized isometric and isokinetic torques from the hip extensors, knee extensors, and ankle plantar flexors.ResultsCompared with the NTM group, the TM group exhibited 30.0% and 33.5% reduction in lower-extremity isometric and isokinetic NETforces, respectively. Isometric and isokinetic NETforce cutoff points for task modifications were ≤4.24 and 2.77 N·m/kg body weight, respectively. The isometric and isokinetic models both yielded sensitivity and specificity values of 74.1% and 80.8%, respectively (positive likelihood ratio=3.852, 95% confidence interval=1.699–8.735; negative likelihood ratio=0.321, 95% confidence interval=0.167–0.618). Isometric and isokinetic NETforces were significantly associated with task modifications (odds ratio=2.50 and 2.42, respectively).LimitationsThe cross-sectional design of this study does not allow for a test of causal relationships. This study used a modest yet adequate sample size that may limit generalization of the results.ConclusionsIsometric and isokinetic NETforce cutoff points provide quantifiable biomarkers that discriminate community-dwelling older adults who modify daily tasks from those who do not.


2021 ◽  
Vol 2 ◽  
Author(s):  
Ranjana K. Mehta ◽  
Joohyun Rhee

Background: Sex differences in neuromuscular fatigue is well-documented, however the underlying mechanisms remain understudied, particularly for the aging population.Objective: This study investigated sex differences in fatigability of the upper and lower extremity of older adults using a neuroergonomics approach.Methods: Thirty community-dwelling older adults (65 years or older; 15 M, 15 F) performed intermittent submaximal fatiguing handgrip and knee extension exercises until voluntary exhaustion on separate days. Muscle activity from prime muscles of the hand/arm and knee extensors were monitored using electromyography, neural activity from the frontal, motor, and sensory areas were monitored using functional near infrared spectroscopy, and force output were obtained.Results: While older males were stronger than females across both muscle groups, they exhibited longer endurance times and greater strength loss during knee extension exercises. These lower extremity findings were associated with greater force complexity over time and concomitant increase in left motor and right sensory motor regions. While fatigability during handgrip exercises was comparable across sexes, older females exhibited concurrent increases in the activation of the ipsilateral motor regions over time.Discussion: We identified differences in the underlying central neural strategies adopted by males and females in maintaining downstream motor outputs during handgrip fatigue that were not evident with traditional ergonomics measures. Additionally, enhanced neural activation in males during knee exercises that accompanied longer time to exhaustion point to potential rehabilitation/exercise strategies to improve neuromotor outcomes in more fatigable older adults.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francisco Félix Caballero ◽  
Ellen A. Struijk ◽  
Alberto Lana ◽  
Antonio Buño ◽  
Fernando Rodríguez-Artalejo ◽  
...  

AbstractElevated concentrations of acylcarnitines have been associated with higher risk of obesity, type 2 diabetes and cardiovascular disease. The aim of the present study was to assess the association between L-carnitine and acylcarnitine profiles, and 2-year risk of incident lower-extremity functional impairment (LEFI). This case–control study is nested in the Seniors-ENRICA cohort of community-dwelling older adults, which included 43 incident cases of LEFI and 86 age- and sex- matched controls. LEFI was assessed with the Short Physical Performance Battery. Plasma L-carnitine and 28 acylcarnitine species were measured. After adjusting for potential confounders, medium-chain acylcarnitines levels were associated with 2-year incidence of LEFI [odds ratio per 1-SD increase: 1.69; 95% confidence interval: 1.08, 2.64; p = 0.02]. Similar results were observed for long-chain acylcarnitines [odds ratio per 1-SD increase: 1.70; 95% confidence interval: 1.03, 2.80; p = 0.04]. Stratified analyses showed a stronger association between medium- and long-chain acylcarnitines and incidence of LEFI among those with body mass index and energy intake below the median value. In conclusion, higher plasma concentrations of medium- and long-chain acylcarnitines were associated with higher risk of LEFI. Given the role of these molecules on mitochondrial transport of fatty acids, our results suggest that bioenergetics dysbalance contributes to LEFI.


2020 ◽  
pp. 104973152098235
Author(s):  
Kuei-Min Chen ◽  
Hui-Fen Hsu ◽  
Li-Yen Yang ◽  
Chiang-Ching Chang ◽  
Yu-Ming Chen ◽  
...  

Purpose: This study aimed to test the effectiveness of High-Need Community-Dwelling Older Adults Care Delivery Model (HCOACDM) in Taiwan. Methods: A cluster randomized controlled trial with repeated measures design was conducted in eight community care centers, involving 145 high-need older adults who were assigned to the intervention group or comparison group. The HCOACDM was provided over 6 months. Functional ability, quality of life, depressive symptoms, and health care and social service utilizations were measured at baseline, at 3 months, and 6 months into the intervention. The participants’ satisfaction was measured at the end of 6-month intervention. Results: Positive effects were shown on all variables in the intervention group at both the 3-month and 6-month intervals (all p < .05). The intervention group had a higher satisfaction with care delivery than the comparison group ( p < .05). Discussion: The promising findings supported a long-term implementation of the HCOACDM as applicable and beneficial.


Author(s):  
Chisato Hayashi ◽  
Soshiro Ogata ◽  
Tadashi Okano ◽  
Hiromitsu Toyoda ◽  
Sonoe Mashino

Abstract Background The effects of group exercise on the physical function of community-dwelling older adults remain unclear. The changes in lower extremity muscle strength, timed up and go (TUG) time, and the motor fitness scale (MFS), over time, among older adults who expressed a willingness to participate in community-based physical exercise groups, were determined using multilevel modelling. Methods We analyzed data of 2407 older adults between April 2010 and December 2019 from the registry of physical tests of community-based physical exercise groups. We conducted a retrospective cohort study to assess the effect of physical exercise on lower extremity muscle strength, TUG time, and MFS scores. The durations of the exercises were evaluated by frequency of physical test’s participate. Results A deterioration in lower extremity muscle strength was found in the short-term participant group only. However, in the mid-term and long-term participation groups, lower extremity muscle strength showed a trend of improvement. The TUG time and the MFS score were negatively correlated with increasing age in both groups divided by the duration of participation. However, there was a slower rate of deterioration in the long-term participation group. Discussion Lower extremity muscle strength, TUG time, and MFS scores decline with increasing age and there were differences in the slope of deterioration that depended on the duration of participation in community-based group exercise. Conclusion Participation in group exercise improved lower extremity muscle strength, TUG time, and MFS scores of older adults living in a community. The positive effects of group exercise were dependent on long-term participation.


2018 ◽  
Vol 74 (4) ◽  
pp. 556-559 ◽  
Author(s):  
Marla K Beauchamp ◽  
Rachel E Ward ◽  
Alan M Jette ◽  
Jonathan F Bean

Abstract Background The Late-Life Function and Disability Instrument (LLFDI) is a well-validated and frequently used patient-reported outcome for older adults. The aim of this study was to estimate the minimal clinically important difference (MCID) of the LLFDI-Function Component (LLFDI-FC) and its subscales among community-dwelling older adults with mobility limitations. Methods We performed a secondary analysis of the Boston Rehabilitative Impairment Study of the Elderly, a longitudinal cohort study of older adults with mobility limitations residing in the community. The MCID for each LLFDI-FC scale over 1 year of follow-up was estimated using both anchor- and distribution-based methods, including mean change scores on a patient-reported global rating of change in function scale, the standard error of measurement (SEM), and the minimal detectable change with 90% confidence (MDC90). Results Data from 320 older adults were used in the analysis (mean age 76 years, 69% female, mean of four chronic conditions). Meaningful change estimates for “small change” based on the global rating of change and SEM were 2, 3, 4, and 4 points for the LLFDI-FC overall function scale and basic lower-extremity, advanced lower-extremity, and upper-extremity subscales, respectively. Estimates for “substantial change” based on the global rating of change and minimal detectable change with 90% confidence were 5, 6, 9, and 10 points for the overall function scale and basic lower-extremity, advanced lower-extremity, and upper-extremity subscales, respectively. Conclusion This study provides the first MCID estimates for the LLFDI-FC, a widely used patient-reported measure of function. These values can be used to interpret the outcomes of longitudinal investigations of functional status in similar populations of community-dwelling older adults.


Author(s):  
Pamela M Dunlap ◽  
Andrea L Rosso ◽  
Xiaonan Zhu ◽  
Brooke N Klatt ◽  
Jennifer S Brach

Abstract Background It is important to understand the factors associated with life space mobility so that mobility disability can be prevented/treated. The purpose of this study was to identify the association between mobility determinants and life space among older adults. Methods This study was a cross-sectional analysis of 249 community-dwelling older adults (mean age=77.4 years, 65.5% female, 88% white) who were recruited for a randomized, controlled, clinical intervention trial. Associations between cognitive, physical, psychosocial, financial, and environmental mobility determinants and the Life Space Assessment (LSA) at baseline were determined using Spearman’s correlation coefficients and one-way analysis of variance. Multivariate analysis was performed using multivariable linear regression models. Results The mean LSA score for the sample was 75.3 (SD=17.8). Personal factors (age, gender, education, comorbidities), cognitive (Trail Making Test A and B), physical (gait speed, lower extremity power, Six Minute Walk Test, Figure of 8 Walk Test, tandem stance, energy cost of walking, and Late Life Function and Disability Function Scale), psychosocial (Modified Gait Efficacy Scale), and financial (neighborhood socio-economic status) domains of mobility were significantly associated with LSA score. In the final regression model, age (β=-0.43), lower extremity power (β=0.03), gait efficacy (β=0.19), and energy cost of walking (β=-57.41) were associated with life space (R 2=0.238). Conclusions Younger age, greater lower extremity power, more confidence in walking, and lower energy cost of walking were associated with greater life space. Clinicians treating individuals with mobility disability should consider personal, physical, and psychosocial factors assessing barriers to life space mobility.


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