Search results for "Muscle"
showing 10 items of 3397 documents
Changes in neural drive to calf muscles during steady submaximal contractions after repeated static stretches
2021
Key points: Repeated static-stretching interventions consistently increase the range of motion about a joint and decrease total joint stiffness, but findings on the changes in muscle and connective-tissue properties are mixed. The influence of these stretch-induced changes on muscle function at submaximal forces is unknown. To address this gap in knowledge, the changes in neural drive to the plantar flexor muscles after a static-stretch intervention were estimated. Neural drive to the plantar flexor muscles during a low-force contraction increased after repeated static stretches. These findings suggest that adjustments in motor unit activity are necessary at low forces to accommodate reduct…
Core Muscle Activity, Exercise Preference, and Perceived Exertion during Core Exercise with Elastic Resistance versus Machine
2015
Objectives. To investigate core muscle activity, exercise preferences, and perceived exertion during two selected core exercises performed with elastic resistance versus a conventional training machine.Methods. 17 untrained men aged 26–67 years participated in surface electromyography (EMG) measurements of five core muscles during torso-twists performed from left to right with elastic resistance and in the machine, respectively. The order of the exercises was randomized and each exercise consisted of 3 repetitions performed at a 10 RM load. EMG amplitude was normalized (nEMG) to maximum voluntary isometric contraction (MVC).Results. A higher right erector spinae activity in the elastic exer…
Home-Based Resistance Training for Older Subjects during the COVID-19 Outbreak in Italy: Preliminary Results of a Six-Months RCT.
2020
Background. The aim of this study was to evaluate the effect of a six-month home-based resistance-training program on muscle health and physical performance in healthy older subjects during the unique condition of home confinement caused by the COVID-19 pandemic. Methods. This was a randomized-controlled study that enrolled older participants that were allocated to either an experimental group performing the six-months exercise prescription (EXE) or a control group (CON). At the beginning (PRE), and after 6 months (POST), participants were assessed for muscle strength, balance, gait assessment and body composition by dual energy X-ray absorptiometry and magnetic resonance imaging. Normality…
Effect of inhibition of the electrogenic Na+/K+ pump on the mechanical activity in the rat uterus.
1996
The effects of ouabain and K(+)-free solution were studied in estrogen-primed rat uterine strips under resting tone or repeatedly stimulated with KCl, acetylcholine or oxytocin applied for 20 minutes at 60 minute intervals. These effects were compared with those of the K+ channel opener cromakalim. In preparations under resting tone, ouabain (0.1 mM and 0.3 mM) induced rhythmic contractions which disappeared after 20-30 minutes whereas at a higher concentration (1 mM) it evoked a rapid, phasic response followed by a small tonic contraction. Exposure of the strip to a K(+)-free solution induced either rhythmic waves, which ceased after 8-10 minutes, or a single phasic contraction which was f…
Body composition and muscle performance during menopause and hormone replacement therapy.
2003
Menopausal transition is characterized by ovarian failure and its consequent decrease in female sex steroid production. Earlier studies suggest that an increase and redistribution of body fat during menopause predispose women to cardiovascular disease and metabolic syndrome. In addition, peri- and post-menopausal women seem to have less lean body mass (LBM) compared with pre-menopausal women. Accordingly, a changing ovarian hormonal status may accelerate the loss of muscle mass and result in decreased muscle performance and functional capacity. Hormone replacement therapy (HRT) has been used to treat menopausal symptoms and as a primary prevention therapy in chronic conditions. Inconsistent…
Handgrip Strength Cannot Be Assumed a Proxy for Overall Muscle Strength
2018
OBJECTIVES: Dynapenia, low muscle strength, is predictive for negative health outcomes and is usually expressed as handgrip strength (HGS). Whether HGS can be a proxy for overall muscle strength and whether this depends on age and health status is controversial. This study assessed the agreement between HGS and knee extension strength (KES) in populations differing in age and health status.DESIGN: Data were retrieved from 5 cohorts.SETTING AND PARTICIPANTS: Community, geriatric outpatient clinics, and a hospital. Five cohorts (960 individuals, 49.8% male) encompassing healthy young and older individuals, geriatric outpatients, and older individuals post hip fracture were included.MEASURES: …
Muscle adenylate kinase in Duchenne muscular dystrophy
1986
Abstract On the basis of electrophoretic and enzyme inhibition studies it was postulated that an aberrant adenylate kinase occurs in muscle and serum of patients with Duchenne muscular dystrophy (Schirmer, R.H. and Thuma, E. (1972) Biochim. Biophys. Acta 268, 92–97; Hamada, M. et al. (1981) Biochim. Biophys. Acta 660, 227–237; Hamada et al. (1985) J. Biol. Chem. 260, 11595–11602. On the basis of the following results we conclude that Duchenne muscular dystrophy patients do not possess an unusual adenylate kinase isoenzyme. (1) In muscle biopsies from five Duchenne patients, the electrophoretic mobility of adenylate kinase and the inhibition of the enzyme by P 1 , P 5 -di(adenosine-5′)pentap…
Postural Sensorimotor Control on Anorectal Pressures and Pelvic Floor Muscle Tone and Strength: Effects of a Single 5P® LOGSURF Session. A Cross-Sect…
2021
Pelvic floor dysfunction (PFD) is a functional condition present most frequently in women. Despite pelvic floor muscle training being considered by the International Continence Society (ICS) as the first-line treatment in uncomplicated urinary incontinence, other more comprehensive postural methods as 5P® LOGSURF have emerged. This preliminary cross-sectional study explores the effects of a single 5P® LOGSURF session on pelvic floor muscle (PFM) tone and strength (MVC), resting anal tone, intrarectal pressure, and deep abdominal muscles activation. Thirty women were included (11 without PFD and 19 with PFD). Primary outcome measures were PFM tone, PFM MVC and resting anal tone and secondary…
The comparison of cold-water immersion and cold air therapy on maximal cycling performance and recovery markers following strength exercises
2016
This study examined the effects of cold-water immersion (CWI) and cold air therapy (CAT) on maximal cycling performance (i.e. anaerobic power) and markers of muscle damage following a strength training session. Twenty endurance-trained but strength-untrained male (n = 10) and female (n = 10) participants were randomised into either: CWI (15 min in 14 °C water to iliac crest) or CAT (15 min in 14 °C air) immediately following strength training (i.e. 3 sets of leg press, leg extensions and leg curls at 6 repetition maximum, respectively). Creatine kinase, muscle soreness and fatigue, isometric knee extensor and flexor torque and cycling anaerobic power were measured prior to, immediately afte…
Effects of nicotine receptor agonists on acetylcholine release from the isolated motor nerve, small intestine and trachea of rats and guinea-pigs
1992
The effects of nicotine receptor agonists on the release of [3H]acetylcholine from the phrenic nerve, the small intestine and the trachea were investigated to characterize neuronal nicotine receptors within the peripheral nervous system. Contraction of the indirectly-stimulated hemidiaphragm was recorded to investigate desensitization of the postsynaptic muscular nicotine receptors. Nicotine, cytisine, 1,1-dimethyl-4-phenylpiperazinium and 2-(4-aminophenyl)-ethyl-trimethyl-ammoniumiodide caused a concentration-dependent (0.1-30 microM) increase in evoked [3H]acetylcholine release from the phrenic nerve, whereby bell-shaped concentration-response curves were obtained. The rank order of decre…