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Leg Power (leg + power)
Selected AbstractsThe Relationship Between Leg Power and Physical Performance in Mobility-Limited Older PeopleJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2002Jonathan F. Bean Md MS OBJECTIVES: The purpose of this study was to assess the influence of leg power and leg strength on the physical performance of community-dwelling mobility-limited older people. DESIGN: Cross-sectional analysis of baseline data from a 12-week randomized controlled exercise-intervention study. SETTING: Exercise laboratory within the Department of Health Science of an urban university. PARTICIPANTS: Forty-five community-dwelling mobility-limited people (34 women, 11 men), aged 65 to 83. MEASUREMENTS: Health status, depression, cognition, physical activity, and falls efficacy; physiological measures of lower extremity strength and power; and measures of physical performance. RESULTS: Through bivariate analyses, leg power was significantly associated with physical performance as measured by stair-climb time, chair-stand time, tandem gait, habitual gait, maximal gait, and the short physical performance battery describing between 12% and 45% of the variance (R2). Although leg power and leg strength were greatly correlated (r = .89) in a comparison of bivariate analyses of strength or power with physical performance, leg power modeled up to 8% more of the variance for five of six physical performance measures. Despite limitations in sample size, it appeared that, through quadratic modeling, the influence of leg power on physical performance was curvilinear. Using separate multivariate analyses, partial R2 values for leg power and leg strength were compared, demonstrating that leg power accounted for 2% to 8% more of the variance with all measures of physical performance. CONCLUSION: Leg power is an important factor influencing the physical performance of mobility-limited older people. Although related to strength, it is a separate attribute that may exert a greater influence on physical performance. These findings have important implications for clinicians practicing geriatric rehabilitation. J Am Geriatr Soc 50:461,467, 2002. [source] Changes in Muscle Mass, Muscle Strength, and Power but Not Physical Function Are Related to Testosterone Dose in Healthy Older MenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2008Thomas W. Storer PhD OBJECTIVES: To examine the effect of graded doses of testosterone on physical function and muscle performance in healthy, older men. DESIGN: Randomized, double-blind, placebo-controlled clinical trial. SETTING: General clinical research center. PARTICIPANTS: Community-dwelling healthy men aged 60 to 75 (N=44). INTERVENTION: Monthly treatment with a gonadotropin-releasing hormone agonist plus 25, 50, 125, or 300 mg/wk of intramuscular injections of testosterone enanthate for 20 weeks. MEASUREMENTS: Skeletal muscle mass (SMM) was estimated using dual-energy X-ray absorptiometry. Leg press strength was measured by one repetition maximum, leg power by Nottingham Leg Rig, and muscle fatigability by repetitions to failure in the leg press exercise. Stair climbing, 6-meter and 400-meter walking speed, and a timed-up-and-go (TUG) test were used to assess physical function. RESULTS: Significant testosterone dose- and concentration-dependent increases were observed in SMM (P<.001) and maximal strength (P=.001) but not muscle fatigability. Leg power also increased dose-dependently (P=.048). In contrast, changes in self-selected normal and fast walking speed over 6 or 400 meters, stair climbing power, and time for the TUG were not significantly related to testosterone dose, testosterone concentrations, or changes in muscle strength or power, or SMM. CONCLUSION: Testosterone administration was associated with dose-dependent increases in SMM, leg strength, and power but did not improve muscle fatigability or physical function. The observation that physical function scores did not improve linearly with strength suggests that these high-functioning older men were already in the asymptotic region of the curve describing the relationship between physical function and strength. [source] Associations Between Lower Extremity Ischemia, Upper and Lower Extremity Strength, and Functional Impairment with Peripheral Arterial DiseaseJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2008Mary M. McDermott MD OBJECTIVES: To identify associations between lower extremity ischemia and leg strength, leg power, and hand grip in persons with and without lower extremity peripheral arterial disease (PAD). To determine whether poorer strength may mediate poorer lower extremity performance in persons with lower arterial brachial index (ABI) levels. DESIGN: Cross-sectional. SETTING: Academic medical centers. PARTICIPANTS: Four hundred twenty-four persons with PAD and 271 without PAD. MEASUREMENTS: Isometric knee extension and plantarflexion strength and handgrip strength were measured using a computer-linked strength chair. Knee extension power was measured using the Nottingham leg rig. ABI, 6-minute walk, and usual and fastest 4-m walking velocity were measured. Results were adjusted for potential confounders. RESULTS: Lower ABI values were associated with lower plantarflexion strength (P trend=.04) and lower knee extension power (P trend <.001). There were no significant associations between ABI and handgrip or knee extension isometric strength. Significant associations between ABI and measures of lower extremity performance were attenuated after additional adjustment for measures of strength. CONCLUSION: These results are consistent with the hypothesis that lower extremity ischemia impairs strength specifically in distal lower extremity muscles. Associations between lower extremity ischemia and impaired lower extremity strength may mediate associations between lower ABI values and greater functional impairment. [source] The Relationship Between Leg Power and Physical Performance in Mobility-Limited Older PeopleJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2002Jonathan F. Bean Md MS OBJECTIVES: The purpose of this study was to assess the influence of leg power and leg strength on the physical performance of community-dwelling mobility-limited older people. DESIGN: Cross-sectional analysis of baseline data from a 12-week randomized controlled exercise-intervention study. SETTING: Exercise laboratory within the Department of Health Science of an urban university. PARTICIPANTS: Forty-five community-dwelling mobility-limited people (34 women, 11 men), aged 65 to 83. MEASUREMENTS: Health status, depression, cognition, physical activity, and falls efficacy; physiological measures of lower extremity strength and power; and measures of physical performance. RESULTS: Through bivariate analyses, leg power was significantly associated with physical performance as measured by stair-climb time, chair-stand time, tandem gait, habitual gait, maximal gait, and the short physical performance battery describing between 12% and 45% of the variance (R2). Although leg power and leg strength were greatly correlated (r = .89) in a comparison of bivariate analyses of strength or power with physical performance, leg power modeled up to 8% more of the variance for five of six physical performance measures. Despite limitations in sample size, it appeared that, through quadratic modeling, the influence of leg power on physical performance was curvilinear. Using separate multivariate analyses, partial R2 values for leg power and leg strength were compared, demonstrating that leg power accounted for 2% to 8% more of the variance with all measures of physical performance. CONCLUSION: Leg power is an important factor influencing the physical performance of mobility-limited older people. Although related to strength, it is a separate attribute that may exert a greater influence on physical performance. These findings have important implications for clinicians practicing geriatric rehabilitation. J Am Geriatr Soc 50:461,467, 2002. [source] Physical Performance and Risk of Hip Fractures in Older Men,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2008Peggy Mannen Cawthon Abstract The aim of these analyses was to describe the association between physical performance and risk of hip fractures in older men. Performance on five physical function exams (leg power, grip strength, usual walking pace, narrow walk balance test, and five repeated chair stands) was assessed in 5902 men ,65 yr of age. Performance (time to complete or strength) was analyzed as quartiles, with an additional category for unable to complete the measure, in proportional hazards models. Follow-up averaged 5.3 yr; 77 incident hip fractures were confirmed by physician review of radiology reports. Poor physical performance was associated with an increased risk of hip fracture. In particular, repeated chair stand performance was strongly related to hip fracture risk. Men unable to complete this exam were much more likely to experience a hip fracture than men in the fastest quartile of this test (multivariate hazard ratio [MHR]: 8.15; 95% CI: 2.65, 25.03). Men with the worst performance (weakest/slowest quartile or unable) on at least three exams had an increased risk of hip fracture compared with men with higher functioning (MHR: 3.14, 95% CI: 1.46, 6.73). Nearly two thirds of the hip fractures (N = 49, 64%) occurred in men with poor performance on at least three exams. Poor physical function is independently associated with an increased risk of hip fracture in older men. The repeated chair stands exam should be considered in clinical settings for evaluation of hip fracture risk. Concurrent poor performance on multiple physical function exams is associated with an increased risk of hip fractures. [source] Ambulation in labour and delivery mode: a randomised controlled trial of high-dose vs mobile epidural analgesia,ANAESTHESIA, Issue 3 2009M. J. A. Wilson Summary Compared to high-dose epidurals where mobility is impossible, mobile epidurals have been shown to reduce instrumental vaginal delivery rates. The mechanism for this benefit may depend on women walking or adopting upright postures during labour. We investigated maternal motor power and ambulation of 1052 primparous women randomised to high-dose epidural (Control), Combined Spinal Epidural (CSE) or Low-Dose Infusion (LDI) as a pre-specified, secondary outcome of the Comparative Obstetric Mobile Epidural Trial. Modified Bromage power scores and the level of mobility a woman actually achieved were recorded each hour after epidural placement during first and second stage, until delivery. Relative to control, significantly more women maintained normal leg power throughout labour in both mobile groups and significantly more women with CSE maintained superior leg power for longer than with LDI. Observational analysis did not demonstrate an association between the level of ambulation a woman actually achieved after epidural placement and delivery mode. [source] | ||||||||||