In sports medicine, neuromuscular electrical stimulation (NMES) has been used for muscle strengthening, maintenance of muscle mass and strength during prolonged periods of immobilisation, selective muscle retraining, and the control of oedema. A wide variety of stimulators, including the burst-modulated alternating current ('Russian stimulator'), twin-spiked monophasic pulsed current and biphas...

Findings of the studies on relationship between isometric handgrip contraction and changes in cerebral blood flow (CBF) are contradictory. The aim study was to evaluate CBF during one minute a maximal contraction. Our main hypothesis that test will cause decrease related strength. protocol included transcranial Doppler ultrasound measurement middle arterial mean velocity (Vmean) with concomitan...

A cholinergic (muscarinic) contribution to the initial circulatory response to exercise in humans remains controversial. Herein, we posit that this may be due to exercise mode with a cholinergic contribution being important during isometric handgrip exercise, where the hyperemic response of the muscle is relatively small compared with the onset of leg cycling, where a marked increase in muscle ...

Postactivation potentiation (PAP), a mechanism by which the torque of a muscle twitch is increased following a conditioning contraction, is well documented in muscular physiology, but little is known about its effect on the maximal rate of torque development and functional significance during voluntary movements. The objective of this study was to investigate the PAP effect on the rate of isome...

Supraspinal fatigue, defined as an exercise-induced decline in force caused by suboptimal output from the motor cortex, accounts for over one-quarter of the force loss after fatiguing contractions of the knee extensors in normoxia. We tested the hypothesis that the relative contribution of supraspinal fatigue would be elevated with increasing severities of acute hypoxia. On separate days, 11 he...

Liao, T.-J. and Nishikawa, H. The Variation of Action Potential and Impedance in Human Skeletal Muscle during Voluntary Contraction. Tohoku J. Exp. Med., 1994, 173 (3), 303-309 We used an insulated acupuncture needle to deliver a 20 kHz alternative current to detect the changes on the electromyogram (EMG) and deep muscle impedance. We found that impedance increased (with a duration of 224.1±75....

1. In keeping with the 'muscular wisdom hypothesis', many studies have documented that the firing rate of the majority of motor units decreased during fatiguing isometric contractions. The present study investigated whether the application of periodic muscle vibration, which strongly activates muscle spindles, would alter the modulation of motor unit firing rate during submaximal fatiguing isom...

Purpose: The present study aimed to investigate the effect of voluntary and electrically stimulated quadriceps muscle fatigue on postural control. Methods: Sixteen healthy young males participated in this quasi-experimental study. All subjects performed two fatiguing exercises with equal intensity of isometric maximal voluntary contraction: Voluntary (VOL) and Electrical Stimulation (ES). The ...

The influence of contraction type on the human ability to use the torque capacity of skeletal muscle during explosive efforts has not been documented. Fourteen male participants completed explosive voluntary contractions of the knee extensors in four separate conditions: concentric (CON) and eccentric (ECC); and isometric at two knee angles (101°, ISO101 and 155°, ISO155). In each condition, to...