Search results for "electromyography"
showing 10 items of 672 documents
Effect of exhausting stretch-shortening cycle exercise on the time course of mechanical behaviour in the drop jump: possible role of muscle damage.
1999
The purpose of the present study was to investigate the effect of stretch-shortening-cycle-induced muscle damage on the time course of mechanical behaviour in the drop jump. Ten healthy male subjects performed submaximal stretch-shortening cycle (SSC) exercise on a special sledge apparatus. Exhaustion occurred on average within 3 min. A drop jump (DJ) test from a 50-cm height was performed before and immediately after the sledge exercise as well as 2 h, 2 days and 4 days later. The fatigue exercise showed relatively high blood lactate concentration [12.5 (SD 2.6) mmol · 1−1] and an increase of serum creatine kinase (CK) activity delayed by 2 days [540 (SD 407) U · 1−1]. The initial decline …
Neuromuscular Adaptations to Same-Session Combined Endurance and Strength Training in Recreational Endurance Runners
2016
This study examined neuromuscular adaptations in recreational endurance runners during 24 weeks of same-session combined endurance and strength training (E+S, n=13) vs. endurance training only (E, n=14). Endurance training was similar in the 2 groups (4-6x/week). Additional maximal and explosive strength training was performed in E+S always after incremental endurance running sessions (35-45 min, 65-85% HRmax). Maximal dynamic leg press strength remained statistically unaltered in E+S but decreased in E at week 24 (-5±5%, p=0.014, btw-groups at week 12 and 24, p=0.014 and 0.011). Isometric leg press and unilateral knee extension force, EMG of knee extensors and voluntary activation remained…
Neuromuscular Effects to 6 Weeks of Loaded Countermovement Jumping With Traditional and Daily Undulating Periodization.
2018
Ullrich, B, Pelzer, T, and Pfeiffer, M. Neuromuscular effects to 6 weeks of loaded countermovement jumping with traditional and daily undulating periodization. J Strength Cond Res 32(3): 660-674, 2018-Loaded vertical jumps are routinely used to enhance athlete's power production in the lower extremity and to optimize jumping and sprinting performance. This study compared traditional (TP) and daily undulating (DUP) periodization on muscle strength, jumping performance, electromyographic (EMG) muscle activity, and muscle architecture during preseason loaded jump training. Twenty-two athletes from different team sports (age: 24.3 ± 2.6 years, height: 175.9 ± 7.5 cm, body mass: 72.2 ± 8.4 kg, 1…
Electromyographical and Perceptual Responses to Different Resistance Intensities in a Squat Protocol: Does Performing Sets to Failure With Light Load…
2015
This investigation examined peak motor unit activity during sets that differed in resistance (50, 70, or 90% 1 repetition maximum [1RM]). Ten resistance-trained men (age, 23 ± 3 years; height, 187 ± 7 cm; body mass, 91.5 ± 6.9 kg; squat 1RM, 141 ± 28 kg) were assessed by electromyography (EMG) on the vastus lateralis and vastus medialis muscles in a randomized within-subject experiment consisting of 2 test visits: a drop-set day and a single-set day using only the 50% of 1RM intensity performed to failure. At the start of each day, subjects performed 2 submaximal repetition sets (50% 1RM × 10 repetitions and 70% 1RM × 7 repetitions). On the drop-set day, subjects performed 3 consecutive max…
Trunk muscle activity during different variations of the supine plank exercise.
2017
BACKGROUND: Exercises providing neuromuscular challenges of the spinal muscles are desired for core stability, which is important for workers with heavy manual labour as well as people recovering from back pain.PURPOSE: This study evaluated whether using a suspended modality increases trunk muscle activity during unilateral or bilateral isometric supine planks.DESIGN: Cross-sectional.METHODS: Twenty university students participated in this cross-sectional study. Each subject performed four different conditions: bilateral stable supine plank, unilateral stable supine plank, bilateral suspended supine plank and unilateral suspended supine plank. Surface electromyography (EMG) signals were rec…
Lymph flow dynamics in exercising human skeletal muscle as detected by scintography
1997
1. The effects of dynamic and isometric muscle contractions on the lymph flow dynamics in human skeletal muscle were studied with a scintographic method. 2. Radioactively labelled human serum albumin (99mTc-HSA) was injected bilaterally into the vastus lateralis muscles of eight men (n = 16), four of whom had had an endurance training background. The subjects performed 100 submaximal contractions in 10 min as (i) dynamic knee extensions (CONS), (ii) isometric contractions with the knees at full extension (IMExt), or (iii) isometric contractions with knees fixed at 90 deg angle flexion (IMFlex). The exercises were separated by 65 min periods in supine rest. The level of radioactivity at the …
Quadriceps Femoris Torque and EMG Activity in Seated versus Supine Position
2003
To compare voluntary and electrically evoked knee extensor torque, surface electromyography (EMG), and activation level obtained under seated versus supine position, i.e., with shortened versus lengthened rectus femoris (RF) muscle.The knee extensor torque obtained during maximal voluntary contractions (MVC) and after single and paired stimuli applied at rest was measured under seated (i.e., 90 degrees hip angle) and supine (i.e., 180 degrees hip angle) conditions. The associated EMG activity from biarticular RF and monoarticular vasti was also recorded, and activation level was estimated by means of the twitch interpolation technique.Knee extensor MVC was 10.6% higher in the seated compare…
The progression of paraspinal muscle recruitment intensity in localized and global strength training exercises is not based on instability alone.
2011
Abstract Colado JC, Pablos C, Chulvi-Medrano I, Garcia-Masso X, Flandez J, Behm DG. The progression of paraspinal muscle recruitment intensity in localized and global strength training exercises is not based on instability alone. Objective To evaluate electromyographic activity of several paraspinal muscles during localized stabilizing exercises and multijoint or global stabilizing exercises. Design Cross-sectional counterbalanced repeated measures. Setting Research laboratory. Participants Volunteers (N=25) without low-back pain. Intervention Subjects performed (1) localized stabilizing exercises (callisthenic exercises with only body weight as resistance): static lumbar extension, stable …
Thinking about movement hurts: The effect of motor imagery on pain and swelling in people with chronic arm pain
2008
Objective: Chronic painful disease is associated with pain on movement, which is presumed to be caused by noxious stimulation. We investigated whether motor imagery, in the absence of movement, increases symptoms in patients with chronic arm pain. Methods: Thirty‐seven subjects performed a motor imagery task. Pain and swelling were measured before, after, and 60 minutes after the task. Electromyography findings verified no muscle activity. Patients with complex regional pain syndrome (CRPS) were compared with those with non‐CRPS pain. Secondary variables from clinical, psychophysical, and cognitive domains were related to change in symptoms using linear regression. Results: Motor imagery in…
Influence of Delay Period Duration on Inhibitory Processes for Response Preparation.
2015
In this study, we examined the dynamics of inhibitory preparatory processes, using a delayed response task in which a cue signaled a left or right index finger (Experiment 1) or hand (Experiment 2) movement in advance of an imperative signal. In Experiment 1, we varied the duration of the delay period (200, 500, and 900 ms). When transcranial magnetic stimulation (TMS) was applied 100 ms before the imperative, motor evoked potentials (MEPs) elicited in the first dorsal interosseous were strongly inhibited. For delays of 500 ms or longer, this inhibition was greater when the targeted muscle was selected compared with when it was not selected. In contrast, the magnitude of inhibition just aft…