Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0392674 (exhaustion)
 13,658 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endurance time (Tlim) is a relevant indicator of muscular resistance to fatigue. It has been recently shown that SEMG changes computed during shorter periods (sub-maximal durations) than the whole test duration could serve to predict Tlim. The aim of the present study was to test whether the prior knowledge of the sub-maximal duration had any influence on Tlim prediction throughout SEMG changes. For this purpose, we compared myoelectric changes estimated over a 30-s isometric contraction whose duration was known by the subjects, to those changes measured during the first 30 s of a test prolonged until exhaustion. The effort intensity was set at 50% of the maximal voluntary isometric torque (MVIT). The myoelectric manifestations of muscle fatigue appeared to change in a similar way during both sessions for temporal and spectral analyses. In conclusion, the prior knowledge of the duration of sustained isometric contraction did not influence the motor unit recruitment strategy throughout surface EMG evaluation. These results confirmed that the use of SEMG changes computed over shorter periods than expected endurance time may be applied to investigate the capability of the initial rate of SEMG changes to predict muscle endurance capacity at 50%MVIT. This may be of particular interest for patient evaluation in the clinical field.
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PMID:SEMG power spectrum changes during a sustained 50% Maximum Voluntary Isometric Torque do not depend upon the prior knowledge of the exercise duration. 1195 82

We propose a new method - twitch force - for estimation of the muscle behavior during voluntary contraction for assessing localized muscle fatigue. The proposed method uses the sEMG peaks as input and the measured force as output. The twitch force, which is a transfer function to generate force, was estimated during fatiguing contraction. We verified the estimated twitch force based on the measured results with electrical stimulation. The participants performed isometric little finger flexion until exhaustion. SEMG was recorded on the flexor digiti minimi brevis muscle for the proposed method and the electrical stimulation electrodes on the ulnar nerve induced involuntary contraction for reference. As the muscle fatigue level increased, the twitch peaks decreased in both methods. The proposed method can be widely used in the quantitative analysis of muscle fatigue during voluntary contraction.
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PMID:Muscle fatigue estimation with twitch force derived from sEMG peaks. 2673 45