Load-dependence of fatigue related changes in tremor around 10 Hz
| Autor: | Christian Wöber, Gerold Ebenbichler, Katharina Kerschan, Wolfgang Löscher, Zeynep Erim, Thomas Nowotny, Andreas Kranzl, Thomas Bochdansky, Josef Kollmitzer, Martin Posch |
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| Rok vydání: | 2000 |
| Předmět: |
Adult
Male medicine.medical_specialty Contraction (grammar) Knee Joint Rest Isometric exercise Motor Activity medicine.disease_cause Functional Laterality Weight-bearing Weight-Bearing Physical medicine and rehabilitation Reference Values Isometric Contraction Physiology (medical) Tremor medicine Humans Low load Contraction time Muscle fatigue business.industry Motor control Sensory Systems Motor unit Neurology Muscle Fatigue Physical Endurance Physical therapy Female Neurology (clinical) business Psychomotor Performance |
| Zdroj: | Clinical Neurophysiology. 111:106-111 |
| ISSN: | 1388-2457 |
| Popis: | Objectives : The aim of the study was to investigate the effects of different loads on tremor around 10 Hz during fatiguing contractions. Methods : Eighteen healthy volunteers performed sustained isometric knee extensions at 30%, 50% and 70% maximum voluntary contraction (MVC). During the fatiguing contractions, mechanical recordings were made with a high-resolution force sensor. Tremor-power was calculated for the 6–20 Hz frequency window as a function of time normalized to endurance time. Results : Initial tremor power was different between the high and low load tasks. Changes of tremor with contraction time differed between the three tasks, in that tremor of the 30% MVC contraction showed the least decrease throughout the sustained contraction, whilst that of the 50% and 70% MVC showed progressively higher decreases. At failure, all 3 contractions merged to the same tremor level. Conclusion : Load-dependent, fatigue-related 6–20 Hz tremor changes during sustained submaximum voluntary contractions seem mainly the consequence of recruitment of new units and fatigue-related properties of the high threshold motor units of muscles. |
| Databáze: | OpenAIRE |
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