Search results for "Exercise."
showing 10 items of 3068 documents
Neuromuscular function during prolonged pedalling exercise at different cadences
2005
Aim: The purpose of the present work was to assess the strategies set by the central nervous system in order to provide the power output required throughout a prolonged (1-h) pedalling exercise performed at different cadences (50 rpm, 110 rpm and the freely chosen cadence). Methods: Neuromuscular (NM) activity of vastus lateralis, rectus femoris, biceps femoris and gastrocnemius lateralis muscles was studied quantitatively [root-mean square (RMS) and mean power frequency (MPF)] and qualitatively (timing of onset and offset of muscle bursts during crank cycle). Results: The present results showed that increased cadence resulted in earlier muscle activation in crank cycle. The influence of ca…
Strength training and neuromuscular function in elderly people with total knee endoprosthesis
2007
The effects of 1 year of intensive strength training on neuromuscular function were studied in elderly people operated for total endoprosthesis (n=30) divided into 3 groups: training pup 1 (TG1, n=11), training pup 2 (TG2, n=10) and control group (CG, n=9). After the operation, TG1 and TG2 trained every second day and the training was controlled by training diaries, and CG performed only conventional exercises by themselves. The overall volume of training in TG2 was 30% greater than in TG1. Neuromuscular function was examined by measuring maximal electromyography (EMG) and maximum voluntary isometric and dynamic strength of the knee extensor and flexor muscles. The range of motion of the kn…
Muscle plasticity after weight and combined (weight + jump) training.
2004
The purpose of this study was to compare the effects of jump training as a complement to weight training on jump performance and muscle strategy during the squat and countermovement jump.Twenty-two male handball players, between the ages of 17 and 24, and in good health, were randomly divided into three groups. Two were trained groups, weight training (WTG) and jump training combined with weight training (CTG), and one was a control group (CG). Maximal isometric force and maximal concentric power were assessed by a supine leg press, squat jump (SJ), counter movement jump (CMJ), and surface EMG was used to determine changes in muscle adaptation before and after the training period.After 6-wk…
Die Aktivität der Rückenstreckmuskulatur beim aufrechten Stehen und beim Sitzen mit standidentischer Rumpfhaltung - eine elektromyographische Studie
2001
Problem: There is a controversial discussion about the loading of the spine by the force of the extending muscles of the back in upright sitting with the back curved as in upright standing. Experimental studies investigating this issue are still lacking. Methods: In the study presented in this paper we measured in 30 subjects the activity of the extending back muscles both in a natural upright standing posture and in sitting with identical posture of the back as recommended in some back training programs. To this end we recorded the electromyographical surface activity of the back muscles at four levels of the spine in both postures. The EMG activities were intraindividually normalized with…
Abdominal Muscle Response During Curl-ups on Both Stable and Labile Surfaces
2000
Abstract Background and Purpose. With the current interest in stability training for the injured low back, the use of labile (movable) surfaces, underneath the subject, to challenge the motor control system is becoming more popular. Little is known about the modulating effects of these surfaces on muscle activity. The purpose of this study was to establish the degree of modulating influence of the type of surface (whether stable or labile) on the mechanics of the abdominal wall. In this study, the amplitude of muscle activity together with the way that the muscles coactivated due to the type of surface under the subject were of interest. Subjects. Eight men (mean age=23.3 years [SD=4.3], me…
Muscle conduction velocity, strength, neural activity, and morphological changes after eccentric and concentric training
2014
This study compared the effects of concentric and eccentric training on neuromuscular adaptations in young subjects. Twenty-two men and women were assigned to one of two groups: concentric (CON, n = 11) and eccentric (ECC, n = 11) training. Training consisted of 6 weeks of isokinetic exercise, performed twice weekly, starting with two sets of eight repetitions, and progressing to five sets of 10 repetitions. Subjects were tested in strength variables [concentric, eccentric, and isometric peak torque (PT), and rate of force development (RFD)], muscle conduction velocity (CV), neuromuscular activity, vastus lateralis (VL) muscle thickness, and echo intensity as determined by ultrasonography. …
Effects of Different Neuromuscular Electrical Stimulation Parameters on Quadriceps Neuromuscular Performance in Competitive Athletes
2017
PURPOSE: To evaluate the effects of six weeks of training with two different types of neuromuscular electrostimulation (NMES) currents on muscle performance in competitive athletes. METHODS: This controlled and randomized clinical trial included 20 athletes, equally divided into three groups: medium frequency current group with 500 μs (MF-500) (n=7), low frequency current group of with 500 μs (PC-500) (n=5) and control group (CG) (n=8). Each group had evaluated, before and after the intervention: the peak torque of knee (PT), muscle thickness and signs of electromyography (EMG) of the vastus lateralis (VL), and the sensory discomfort level (VAS). The training with NMES was performed 3 times…
Catechol-O-Methyltransferase Gene Polymorphism Is Associated with Skeletal Muscle Properties in Older Women Alone and Together with Physical Activity
2008
BackgroundMuscle strength declines on average by one percent annually from midlife on. In postmenopausal women this decrement coincides with a rapid decline in estrogen production. The genetics underlying the effects of estrogen on skeletal muscle remains unclear. In the present study, we examined whether polymorphisms within COMT and ESR1 are associated with muscle properties and assessed their interaction and their combined effects with physical activity.Methodology/principal findingsA cross-sectional data analysis was conducted with 434 63-76-year-old women from the population-based Finnish Twin Study on Aging. Body anthropometry, muscle cross-sectional area (mCSA), isometric hand grip a…
Leg extension power deficit and mobility limitation in women recovering from hip fracture.
2008
OBJECTIVE: After hip fracture, muscle strength and power remain persistently poor, especially in the fractured leg. This study explores whether asymmetrical leg extension power (LEP) deficit affects mobility in women after proximal femoral fracture (PFF). DESIGN: In this observational study, LEP of both legs, 10- and 50-foot walking speed, and stair-climbing speed were measured in 43 women, aged 73-96, at 1 and 13 wks after surgical repair of PFF. Asymmetrical LEP deficit was calculated as (fractured/(sum both legs)) x 100%. RESULTS: Between weeks 1 and 13 after PFF surgery, LEP increased in the fractured and nonfractured legs by 100% and 30%, respectively. Asymmetrical deficit was reduced …
Cardiopulmonary exercise testing in COVID-19 patients at 3 months follow-up☆
2021
Abstract Background Long-term effects of Coronavirus Disease of 2019 (COVID-19) are of utmost relevance. We aimed to determine: 1) the functional capacity of COVID-19 survivors by cardiopulmonary exercise testing (CPET); 2) the characteristics associated with cardiopulmonary exercise testing (CPET) performance; 3) the safety and tolerability of CPET. Methods We prospectively enrolled consecutive patients with laboratory-confirmed COVID-19 from Azienda Sanitaria Locale 3, Genoa. Three months after hospital discharge a complete clinical evaluation, trans-thoracic echocardiography, CPET, pulmonary function tests, and dominant leg extension (DLE) maximal strength measurement were performed. Res…