Electromyographic features of agonists and antagonist muscles of the knee joints during maximal and submaximal isokinetic fatigue
10.3969/j.issn.2095-4344.2015.33.019
- VernacularTitle:膝关节最大和次最大等速运动至疲劳过程中主动肌与拮抗肌肌电特征分析
- Author:
Su ZHANG
;
Feng GAO
- Publication Type:Journal Article
- Keywords:
Knee Joint;
Fatigue;
Electromyography
- From:
Chinese Journal of Tissue Engineering Research
2015;(33):5344-5350
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND:The power output of the human joints depends on the activation of agonists and antagonist muscles around the joints, and the antagonist muscle is involved in physical activity in a co-activated manner, thereby helping to maintain joint stability. But there are less reports on the central nervous system strategies of antagonist co-activation under different muscle contraction modes. OBJECTIVE:To observe the characteristics and differences of surface electromyography (sEMG) of agonists and antagonist muscles of the knee joints during maximal and submaximal isokinetic exercises until fatigue. METHODS:Sixteen students were enroled, who developed the right knee joint fatigue induced by the Biodex isokinetic equipment, and simultaneously sEMG activities of vastus medialis, vastus lateralis and biceps femoris were recorded by the myoelectrical equipment. The RMS (%) and mean frequency were selected to analyze sEMG characteristics. RESULTS AND CONCLUSION:In the maximal isokinetic fatigue, the peak torque was decreased by 40.3% (P < 0.05) and the sEMG activity of agonists gradualy increased and then declined, but the sEMG activity of antagonists kept constant. In the submaximal isokinetic fatigue, the peak torque was decreased by 40.0% (P < 0.05), the sEMG activity of agonists gradualy increased (P < 0.05), and however the sEMG activity of the antagonists initialy increased and then decreased. The RMS and mean frequency of vastus medialis and lateralis as antagonists at selected reciprocal contractions showed no significant changes (P > 0.05). These results suggest that in the different intensities of isokinetic fatigue, the central nervous system employs different neural strategies on agonists and antagonists.
