This research aimed to appreciate whether the mechanomyogram (MMG) may be used to monitor the muscle behavior under fatiguing exercise. The electromyogram (EMG) and MMG were simultaneously recorded from the Biceps and from the Brachioradialis muscles, with surface electrodes EMG, and accelerometer based transducers – MMG, from sixteen subjects. The conclusions are consistent in validating the u...

Unaccustomed eccentric exercise has been shown to impair muscle function, although little is known regarding this impairment on muscle power. The purpose of this study was to investigate changes in neuromuscular properties of the ankle dorsiflexors during and after an eccentric contraction task and throughout recovery in 21 (10 men, 11 women) recreationally active young adults (25.8+/-2.3 yr). ...

We tested the hypothesis that older muscle has greater metabolic economy (ME) in vivo than young, in a manner dependent, in part, on contraction intensity. Twenty young (Y; 24±1 yr, 10 women), 18 older healthy (O; 73±2, 9 women) and 9 older individuals with mild-to-moderate mobility impairment (OI; 74±1, 7 women) received stimulated twitches (2 Hz, 3 min) and performed nonfatiguing voluntary (2...

Not only twitch torque but also the maximal voluntary concentric torque increases after a high-intensity contraction (conditioning contraction). The purpose of this study was to test the hypothesis that the increase in the maximal voluntary concentric torque induced by a conditioning contraction is prominent when tested at fast angular velocities conditions. Twelve healthy male participants per...

BACKGROUND It is unclear whether mental simulation without actual muscle contraction associated with actual motion can increase the excitability of the spinal neural function. OBJECTIVE To determine the best method for mental simulation without actual muscle contraction, we analyzed the F-wave of thenar muscles after stimulating the median nerve by motor imagery whilst holding the sensor of a...

Twenty-one patients with various heart diseases undergoing the coronary sinus catheterization had myocardial blood flow studies before and during isometric handgrip exercise. At 30% of the maximal voluntary contraction (MVC), handgrip increased both coronary sinus blood flow by 19.8% and myocardial O2 consumption by 21.0% on the average as compared to those at rest. At 20% of MVC, the increase ...

OBJECTIVE To evaluate conduction abnormalities in the nerves innervating the proximal muscles in demyelinating neuropathies (DN) using cervical magnetic stimulation. METHODS We applied cervical root magnetic stimulation in the biceps brachii muscles and examined its activity-dependent conduction changes produced by maximal voluntary contraction (MVC) in 12 DN patients (seven chronic inflammat...

Antagonistic muscle pairs cannot be fully activated simultaneously, even with maximal effort, under conditions of voluntary co-contraction, and their muscular activity levels are always below those during agonist contraction with maximal voluntary effort (MVE). Whether the muscular activity level during the task has trainability remains unclear. The present study examined this issue by comparin...

[Purpose] The purpose of this study was to determine the activities of the muscles around the ankle joint during foot gripping. [Subjects] The subjects of this study were 17 healthy females. [Methods] We measured the maximum voluntary contraction (MVC) activities of the soleus muscle, the medial head of the gastrocnemius muscle, and the tibialis anterior muscle, and calculated %IEMG during foot...

[Purpose] This study aimed to identify changes in muscle activation by comparing muscle activities of the affected side (AS) and non-affected side (NAS) during eccentric and concentric exercises in runners with unilateral Achilles tendinopathy. [Subjects] The study included 18 participants consisting of men and women with chronic Achilles tendinopathy in a single leg who had more than 1 year of...