Muscle patterns underlying voluntary modulation of co-contraction

Forearm muscle oxygenation decreases with low levels of voluntary contraction.

The purpose of our investigation was to determine if the near infrared spectroscopy technique was sensitive to changes in tissue oxygenation at low levels of isometric contraction in the extensor carpi radialis brevis muscle. Nine subjects were seated with the right arm abducted to 45 degrees, elbow flexed to 85 degrees, forearm pronated 45 degrees, and wrist and forearm supported on an armrest...

Functional Significance of Force Fluctuation During Voluntary Muscle Contraction

Associative plasticity in human motor cortex during voluntary muscle contraction.

TMS pulses over the hand area of motor cortex activate different subpopulations of synaptic connections if the direction of the induced current in the brain is reversed from posterior-anterior (PA) direction to anterior-posterior (AP). We tested whether this also made a difference to the after-effects of paired associative stimulation (PAS: ulnar nerve stimulation followed 25 ms later by a tran...

Time-Dependent Cortical Activation in Voluntary Muscle Contraction

This study was to characterize dynamic source strength changes estimated from high-density scalp electroencephalogram (EEG) at different phases of a submaximal voluntary muscle contraction. Eight healthy volunteers performed isometric handgrip contractions of the right arm at 20% maximal intensity. Signals of the handgrip force, electromyography (EMG) from the finger flexor and extensor muscles...

Maximal Voluntary Contraction

Miyahara, Y, Naito, H, Ogura, Y, Katamoto, S, and Aoki, J. Effects of proprioceptive neuromuscular facilitation stretching and static stretching on maximal voluntary contraction. J Strength Cond Res 27(1): 195–201, 2013—This study was undertaken to investigate and compare the effects of proprioceptive neuromuscular facilitation (PNF) stretching and static stretching on maximal voluntary contrac...