This study investigates the control mechanisms at the cortical and spinal levels of antagonist coactivation during a submaximal fatiguing contraction of the elbow flexors at 50% of maximal voluntary contraction (MVC). We recorded motor-evoked potentials in the biceps brachii and triceps brachii muscles in response to magnetic stimulation of the motor cortex (MEP) and corticospinal tract (cervic...

This study was designed to reconcile the following clinical observations: subjects with anxiety represented in muscle tension generally have hyperactive tendon jerks. Yet, muscle tension evidenced by incomplete relaxation frequently results in reflex depression and the tendon reflex can only be elicited by having the subject 'relax'. Under consideration were the observations by Hoffmann (1922) ...

The modulation of spinal cord excitability during rhythmic limb movement reflects the neuronal coordination underlying actions of the arms and legs. Integration of network activity in the spinal cord can be assessed by reflex variability between the limbs, an approach so far very little studied. The present work addresses this question by eliciting Hoffmann (H-) reflexes in both limbs to assess...

This study compared the mechanisms that limit the time to failure of a sustained submaximal contraction at 20% of maximum when the elbow flexors either supported an inertial load (position task) or exerted an equivalent constant torque against a rigid restraint (force task). The surface electromyogram (EMG), the motor-evoked potential (MEP) in response to transcranial magnetic stimulation (TMS)...

BACKGROUND There is supportive evidence that multiple sclerosis (MS) could potentially affect the peripheral nervous system. We assessed peripheral sensory and motor nerve involvement in patients with MS by a nerve conduction velocity test. METHODS We studied 75 patients who had a relapsing-remitting or secondary progressive pattern. We measured amplitude, latency, conduction velocity, Hoffma...

Klass, M., N. Guissard, and J. Duchateau. Limiting mechanisms of force production after repetitive dynamic contractions in human triceps surae. J Appl Physiol 96: 1516–1521, 2004. First published November 7, 2003; 10.1152/japplphysiol.01049.2003.—The influence of repetitive dynamic fatiguing contractions on the neuromuscular characteristics of the human triceps surae was investigated in 10 subj...

The influence of repetitive dynamic fatiguing contractions on the neuromuscular characteristics of the human triceps surae was investigated in 10 subjects. The load was 50% of the torque produced during a maximal voluntary contraction, and the exercise ended when the ankle range of motion declined to 50% of control. The maximal torque of the triceps surae and the electromyographic (EMG) activit...

INTRODUCTION The diagnosis of fever syndromes had rested on both objective and subjective feelings of warmth since antiquity, but by the seventeenth century a fast pulse had become the single most common criterion for diagnosing any fever. For instance, in 1692, Thomas Willis was quite explicit about the importance of this diagnostic clue: "First, we consult the Pulse as a Thermometer constitut...