Search results for " Muscle"
showing 10 items of 1495 documents
Lower limb muscle moments and power during recovery from forward loss of balance in male and female single and multiple steppers
2011
Abstract Background Studying recovery responses to loss of balance may help to explain why older adults are susceptible to falls. The purpose of the present study was to assess whether male and female older adults, that use a single or multiple step recovery strategy, differ in the proportion of lower limb strength used and power produced during the stepping phase of balance recovery. Methods Eighty-four community-dwelling older adults (47 men, 37 women) participated in the study. Isometric strength of the ankle, knee and hip joint flexors and extensors was assessed using a dynamometer. Loss of balance was induced by releasing participants from a static forward lean (4 trials at each of 3 f…
Aging-induced Up-regulation of Nuclear Binding Activities of Oxidative Stress Responsive NF-kB Transcription Factor in Mouse Cardiac Muscle
1996
The accumulation of lipofuscin to cardiomyocytes is a classical parameter of aging and is believed to reflect oxidative stress. NF-kB transcription factor complex is one of the cellular sensors which responds to oxidative stress and regulates gene expression. Our purpose was to study whether aging affects the level and distribution of DNA binding activities of NF-kB transcription factors both in cardiac sarcoplasm and nuclear extracts. We used electrophoretic mobility shift assays (EMSA) to characterize the DNA binding activities of NF-kB and two other transcription factors. AP-1 and Sp-1, in the myocardium of 4 months and 24 months old male and female NMRI-mice. The protein levels of p50, …
Plantarflexor Muscle-Tendon Properties are Associated With Mobility in Healthy Older Adults
2015
BACKGROUND: Muscle mass, strength, and power are known determinants of mobility in older adults but there is limited knowledge on the influence of muscle architecture or tendon properties on mobility. The purpose of this study was to examine the relationship between mobility and plantarflexor muscle-tendon properties in healthy older adults.METHODS: A total of 52 subjects (age 70-81 years) were measured for 6-minute walk test (6MWT), timed "up and go"-test (TUG), isometric plantarflexion strength, Achilles tendon stiffness, triceps surae muscle architecture, lower extremity lean mass, isometric leg extension strength, and leg extension power. Partial correlations and multivariate regression…
Effects of different strength training frequencies on maximum strength, body composition and functional capacity in healthy older individuals
2017
There is controversy in the literature regarding the dose-response relationship of strength training in healthy older participants. The present study determined training frequency effects on maximum strength, muscle mass and functional capacity over 6 months following an initial 3-month preparatory strength training period. One-hundred and six 64–75 year old volunteers were randomly assigned to one of four groups; performing strength training one (EX1), two (EX2), or three (EX3) times per week and a non-training control (CON) group. Whole-body strength training was performed using 2–5 sets and 4–12 repetitions per exercise and 7–9 exercises per session. Before and after the intervention, ma…
Quantitative analysis of modified functional muscle–bone unit and back muscle density in patients with lumbar vertebral fracture in Chinese elderly m…
2018
Objectives: Bone mineral density (BMD) is associated with muscle mass and quality, but little research has been done on functional muscle–bone unit and back muscle density in patients with lumbar vertebral fracture. This study used the “modified functional muscle–bone unit” concept and measured back muscle density to investigate muscle–bone interaction difference between the fracture and control group. Methods: This was a case–control study. A total of 52 elderly male patients (mean age 75 years) with lumbar vertebral fracture (cases) and 52 control healthy subjects were enrolled. Cross-sectional area (CSA) and density of paravertebral muscle were measured in quantitative computed tomograph…
L-Carnitine Supplementation and Physical Exercise Restore Age-Associated Decline in Some Mitochondrial Functions in the Rat
2008
In mammals, during the aging process, an atrophy of the muscle fibers, an increase in body fat mass, and a decrease in skeletal muscle oxidative capacities occur. Compounds and activities that interact with lipid oxidative metabolism may be useful in limiting damages that occur in aging muscle. In this study, we evaluated the effect of L-carnitine and physical exercise on several parameters related to muscle physiology. We described that supplementing old rats with L-carnitine at 30 mg/kg body weight for 12 weeks (a) allowed the restoration of L-carnitine level in muscle cells, (b) restored muscle oxidative activity in the soleus, and (c) induced positive changes in body composition: a decr…
Age- and training-related changes in the collagen metabolism of rat skeletal muscle
1989
The effects of ageing and life-long endurance training on the collagen metabolism of skeletal muscle were evaluated in a longitudinal study. Wistar rats performed treadmill running 5 days a week for 2 years. The activities of collagen biosynthesis enzymes, prolyl-4-hydroxylase and galactosylhydroxylysyl glucosyltransferase, were highest in the muscles of the youngest animals, decreased up to the age of 2 months and from then on remained virtually unchanged. The enzyme activity in young animals was higher in the slow collagenous soleus muscle than in the rectus femoris muscle. The enzyme activity in the soleus muscle was higher for older trained rats than older untrained rats. The relative p…
The association between low skeletal muscle mass and delirium: results from the nationwide multi-centre Italian Delirium Day 2017
2021
Abstract Introduction Delirium and sarcopenia are common, although underdiagnosed, geriatric syndromes. Several pathological mechanisms can link delirium and low skeletal muscle mass, but few studies have investigated their association. We aimed to investigate (1) the association between delirium and low skeletal muscle mass and (2) the possible role of calf circumference mass in finding cases with delirium. Methods The analyses were conducted employing the cross-sectional “Delirium Day” initiative, on patient 65 years and older admitted to acute hospital medical wards, emergency departments, rehabilitation wards, nursing homes and hospices in Italy in 2017. Delirium was diagnosed as a 4 + …
Effect of Eight Weeks' Physical Training on Muscle and Connective Tissue of the M. Vastus Lateralis in 69-year-old Men and Women
1977
Five one-hour exercise periods a week for 8 weeks included walking-jogging, swimming, gymnastics and ballgames for 26 healthy male and female 69-year-old pensioners. The mean maximal oxygen uptake of the men increased from 28.9 ml-kg-1-min-1 before training to 32.0 ml-kg-1-min-1 after training and for the women from 27.9 to 31.3 ml-kg-1-min-1. Muscle malate dehydrogenase activity was increased while that for lactate dehydrogenase decreased or remained the same. The activity of these enzymes was higher in the male both before and after training when compared with the female. However, the percentage number of slow twitch muscle fibers was nearly the same in both groups. Prolyl hydroxylase act…
Self-Relevance Appraisal Influences Facial Reactions to Emotional Body Expressions
2013
International audience; People display facial reactions when exposed to others' emotional expressions, but exactly what mechanism mediates these facial reactions remains a debated issue. In this study, we manipulated two critical perceptual features that contribute to determining the significance of others' emotional expressions: the direction of attention (toward or away from the observer) and the intensity of the emotional display. Electromyographic activity over the corrugator muscle was recorded while participants observed videos of neutral to angry body expressions. Self-directed bodies induced greater corrugator activity than other-directed bodies; additionally corrugator activity was…