Electromyography and clinical neurophysiology
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Electromyogr Clin Neurophysiol · Nov 2007
The relationship between skin temperature and neuronal characteristics in the median, ulnar and radial nerves of non-impaired individuals.
The purpose of this study was to evaluate the relationship between the nerve conduction characteristics in the median, ulnar and radial nerves and presenting skin temperature in non-impaired individuals as they were subjected to electrophysiological testing. Previous researchers artificially manipulated the skin temperature and demonstrated that there was a positive relationship between temperature and nerve conduction velocity and a negative correlation between distal latency and evoked motor action potential (EMAP). The sample population was 50 non-impaired individuals derived from a venue in the New York City and Long Island region. ⋯ The data were analyzed using descriptive statistics, the Bonferroni correction factor and correlation statistics. The study showed significant correlation in median motor distal latency, ulnar motor distal latency, ulnar sensory distal latency, median sensory amplitude, and ulnar sensory amplitude. The NCV, the distal latency and the amplitude of the median, ulnar and radial nerves were similar in values to other researchers' normal values.
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Electromyogr Clin Neurophysiol · Nov 2007
Changes in soleus motoneuron pool reflex excitability and surface EMG parameters during fatiguing low- vs. high-intensity isometric contractions.
The fatigue-related changes in soleus motoneuron pool reflex excitability and surface electromyography (EMG) parameters, and maximal voluntary contraction (MVC) force of the plantarflexor (PF) muscles during repeatedly sustained low- (30% MVC) vs. high-intensity (70% MVC) isometric contractions were evaluated Twelve young men with mean (+/- SE) age of 22.4 +/- 0.3 years participated in two fatigue tasks on separate days with at least 1-week interval. The fatigue task consisted of three sustained isometric contractions of PF muscles at a target force level until exhaustion separated with 2-min pause between contractions. M-wave (muscle compound action potential) amplitude (M(max)), Hoffmann reflex maximal amplitude (H(max)) to M-wave amplitude ratio (H(max)/M(max)), and root mean square amplitude (RMS) and median frequency (MF) of EMG power spectrum were recorded from the soleus muscle. ⋯ We conclude that low-intensity isometric contractions, repeatedly sustained to fatigue, resulted in a marked increase in the EMG amplitude and spectral compression without a significant post-fatigue reflex inhibition of soleus motoneuron pool. High-intensity contractions, however, resulted in post-fatigue reflex inhibition of soleus motoneuron pool and less pronounced EMG spectral compression during fatiguing contractions. A failure of neuromuscular transmission-propagation was not evident after repetitive fatiguing isometric contractions.
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Electromyogr Clin Neurophysiol · Nov 2007
Lumbosarcral radiculopathties--the importance of EDX information other than needle electromyography.
This study evaluates the importance of varying electrodiagnostic (EDX) parameters abnormalities in patients with possible lumbosacral radiculopathies (LSR). ⋯ This study emphasizes the importance of EDX studies other than nEMG in the evaluation of patients with possible LSR and supports the value of a computerized mutliparameter methodology in these patients.