Search results for "isometric"
showing 10 items of 535 documents
AB0929 Balance in fibromyalgia is not related with lower limb strength
2017
Background Postural control, that depends on many sensory contributors and motor skills, is altered in people with fibromyalgia (FM) 1–3. Knowing those contributors that could be impaired in this population is important to design an appropriate balance therapy. Objectives Due to the fact that people with FM use to present a strength loss 7, our main goal was to explore the relation between postural control and lower limb strength in this population. Further, the sensory inputs contributors to the postural control were assessed. Methods A cross-sectional study was conducted in a sample of 40 FM patients. A force platform was used to assess postural control under five bipedal conditions: i) e…
Unilateral Conditioning Contractions Enhance Power Output in Elite Short Track Speed Skaters
2018
AbstractThe objective of the present study was to assess the effect of unilateral lower-body-conditioning muscle contractions during multiple sets of fatiguing repeated jumps in elite athletes. Five elite short-track speed-skating athletes performed 9 sets of 6 maximal consecutive jumps on 2 separate occasions: with (COND) and without (CTRL) preliminary voluntary conditioning contractions (CC) 5 min before the beginning of the sets. The CC consisted of 2 consecutive 3 s maximal unilateral isometric squats against a fixed bar, resulting in a 6 s overall isometric contraction per leg. For each set, power output (PO) was measured using a linear position transducer and averaged over the 6 corre…
Effects of Combined Strength and Endurance Training on Body Composition, Physical Fitness, and Serum Hormones During a 6-Month Crisis Management Oper…
2020
Pihlainen, K, Kyröläinen, H, Santtila, M, Ojanen, T, Raitanen, J, and Häkkinen, K. Effects of combined strength and endurance training on body composition, physical fitness, and serum hormones during a 6-month crisis management operation. J Strength Cond Res XX(X): 000-000, 2020-Very few studies have examined the impact of training interventions on soldier readiness during an international military operation. Therefore, the present study investigated the effects of combined strength and endurance training on body composition, physical performance, and hormonal status during a 6-month international military deployment consisting of typical peacekeeping tasks, e.g., patrolling, observation, a…
Changes in electromyographic activity, muscle fibre and force production characteristics during heavy resistance/power strength training in middle-ag…
2001
The effects of a 6-month resistance training (2 day/week) designed to develop both strength and power on neural activation by electromyographic activity (EMG) of the agonist and antagonist knee extensors, muscle fibre proportion and areas of type I, IIa, and IIb of the vastus lateralis (VL) as well as maximal concentric one repetition maximum (1 RM) strength and maximal and explosive isometric strength of the knee extensors were examined. A total of 10 middle-aged men (M40; 42 +/- 2), 11 middle-aged women (W40; 39 +/- 3), 11 elderly men (M70; 72 +/- 3) and 10 elderly women (W70; 67 +/- 3) served as subjects. Maximal and explosive strength values remained unaltered during a 1-month control p…
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…
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…
Short-interval intracortical inhibition is not affected by varying visual feedback in an isometric task in biceps brachii muscle
2013
Short-interval intracortical inhibition (SICI) of the primary motor cortex (M1) appears to play a significant role in skill acquisition. Consequently, it is of interest to find out which factors cause modulation of SICI. Purpose: To establish if visual feedback and force requirements influence SICI. Methods: SICI was assessed from 10 healthy adults (5 males and 5 females aged between 21 and 35 years) in three submaximal isometric elbow flexion torque levels (5%, 20% and 40% of maximal voluntary contraction [MVC]) and with two tasks differing in terms of visual feedback. Single-pulse and paired-pulse motor evoked potentials (MEPs), supramaximal M-wave and background surface electromyogram (s…