Search results for "isometric"
showing 10 items of 535 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…
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…
Fatigue effects of marathon running on neuromuscular performance
2007
Nine experienced endurance runners performed individual marathon runs that involved several tests of neuromuscular performance before, during and after the marathon. The tests were performed with special force platform and dynamometer techniques. The results showed an overall decrease in performance from the marathon. The maximal sprint velocity decreased parabolically during the marathon, reaching the final value of 84% of the pre-marathon one. Similarly, the other test results after marathon indicated that maximal isometric knee extension torque was 78%, the performance in a special rebound test (drop jump) 84% and the 5-jump performance 92% of the pre-marathon values. These reductions we…
Effects of endothelin-1 on the cerebrovascular bed of the goat.
1991
Abstract The aim of the present study was to analyze the effects of endothelin-1 (ET-1) in the cerebrovascular bed of the goat, the importance of endothelial integrity and the contribution of extracellular Ca2+ to these responses. We measured isometric tension and 45Ca2+ uptake in isolated middle cerebral arteries, and cerebral blood flow (CBF) in unanesthetized animals. ET-1 elicited concentration-dependent contractions which were potentiated in arteries without endothelium. Ca2+-free medium and nicardipine inhibited, and Bay K 8644 potentiated the ET-1-induced contractions. ET-1 enhanced 45Ca2+ uptake in isolated arteries. Injections of ET-1 directly into the cerebral circulation decrease…
Acute heavy-resistance exercise–induced pain and neuromuscular fatigue in elderly women with fibromyalgia and in healthy controls: Effects of strengt…
2006
Objective To examine heavy-resistance exercise–induced acute neuromuscular fatigue, blood lactate concentration, and muscle pain in elderly women with fibromyalgia (FM) and in healthy controls before and after a period of strength training. Methods Thirteen elderly women with FM (mean ± SD age 60 ± 2 years) and 10 healthy women (mean ± SD age 64 ± 3 years) performed a heavy-resistance fatiguing protocol (5 sets of leg presses with 10 repetitions maximum) before and after a 21-week strength training period. Maximal isometric force and electromyography (EMG) activity of leg extensors and blood lactate concentration were measured during the loading. Pain was assessed by visual analog scale. Re…
Physical Fitness in Postmenopausal Women with Fibromyalgia
2007
The purpose of this study was to compare physical fitness and health-related quality-of-life between twenty-three postmenopausal women with fibromyalgia (age 58 +/- 3 years) and eleven healthy women (58 +/- 5 years). Aerobic fitness and isometric force of different muscle groups were measured. Functional performance was assessed by walking and stair-climbing times. Symptoms were assessed by visual analog scale and quality-of-life by RAND-36 questionnaire. Women with fibromyalgia had significantly lower isometric force in bilateral leg extensors (1285 vs. 1898 N), unilateral knee extensors (414 vs. 502 N) and flexors (197 vs. 235 N) than healthy women, but no differences were observed in for…
Effectiveness of the PROMUFRA program in pre-frail, community-dwelling older people: A randomized controlled trial.
2020
Abstract This study evaluated the effect of PROMUFRA program on physical frailty, kinanthropometric, muscle function and functional performance variables in pre-frail, community-dwelling older people. Participants (n = 50, 75 ± 7 years) were randomly assigned to two groups: intervention group (IG), and control group (CG). The IG performed multi-component exercise program, focused on high-intensity resistance training (HIRT) combined with self-massage for myofascial release (SMMR) for 12 weeks (2 d.wk−1). Two measurements were performed, at baseline and post-3 months. Participants (n = 43) were analyzed and significant differences were found in group-time interaction for muscle mass (p = 0.0…
Genetic effects in common on maximal walking speed and muscle performance in older women
2007
The purpose was to examine whether maximal walking speed, maximal isometric knee extensor strength, and leg extensor power share genetic or environmental effects in common. The data was collected from 103 monozygotic and 114 dizygotic female twin pairs aged 63–76 years. Maximal walking speed over 10 m was measured in the laboratory corridor using photocells for timing. Isometric knee extensor strength and leg extensor power were measured using an adjustable dynamometer. The genetic models showed that strength, power, and walking speed had a genetic effect in common which accounted for 52% of the variance in strength, 36% in power, and 34% in walking speed. Strength and power had a non-share…
Weight-bearing, muscle loading and bone mineral accrual in pubertal girls--a 2-year longitudinal study.
2007
Abstract Objectives: The mechanical environment is considered to be the most important determinant of bone strength. Local muscle force, in turn, is regarded as the largest source of loading applied to bones. However, the effect of weight-bearing on bone mineral accrual is unclear. Comparing the relationship between muscle force and bone mineral content (BMC) in the upper and lower limbs provides a means of investigating this issue. Subjects and methods : The study group comprised 258 healthy girls aged 10–13 years old at baseline. BMC, lean body mass (LM) and fat body mass (FM) of total body were assessed by dual-energy X-ray absorptiometry at baseline and 2 years after. The maximal isomet…