Acute effects of antagonist muscle PNF stretching on neuromuscular fatigue, strength and electromyography of agonist muscle in knee joint of non-athlete peoples

Abstract

Aim: the purpose of this study was to investigate the acute effects of antagonist muscle PNF stretching onpeak torque, rate of vertical jump height and fatigue of agonist muscle in knee joint of non-athlete subject.Method: fifteen physical education male students (21/7±1/3 yrs, 180/9±7/02 cm, 75/2±9/8 kg) volunteered toparticipate in current study. Subjects were tested for vertical jump height and isokinetic peak torqueproduction during knee extension at 600.s and 3000.s and also tested for isokinetic 25 repetition peak torqueproduction during knee extension at 600 for fatigue testing. Electromyographic data was recorded for thevastus lateralis and biceps femoris muscles during fatigue testing. Paired samples t-tests way used foranalyzing data. Results: statistical results indicated that there was no significant differences betweenstretching groups and non-stretching groups in isokinetic peak torque production during Knee extension at600.s-1 (257 vs 257 N.m; p=0/945) and 3000.s-1 (145 vs 146 N.m; p=0/754). And also no significantdifferences found between stretching groups and non-stretching groups in vertical jump height (54/3 vs 53/1cm; p=0/358), also percentage of median frequency decrease of vastus lateralis muscle was not significant(14/3 vs 4/8 per; p=0/161) and work fatigue of agonist muscles (49/6 vs 49/8 pre; p=0/891). Conclusion:These results indicate that acute PNF stretching of antagonist muscles has no positive effects on peak torque,rate of vertical jump height and fatigue of agonist muscle. Therefore possibly using this method beforeexercise has no positive effects on increasing agonist muscles performance.

Keywords

• acute pnf stretching
• neuromuscular fatigue
• agonist and antagonist muscles
• strength
• electromyography