2019, Volume 15
Effects of lower fatigue protocols on motor neuron excitability in Korea National Team Taekwondo athletes
Eonho Kim1, Seung-Taek Lim2, Keehyun Kim3, Kwangkyu Lee3, Bogeun Lee3, Taejin Kwak3, Minsoo Jeon4, Kijeong Kim5, Daehee Kim3, Jougchul Park3, Joo-Ho Song3
1Department of Physical Education, Dongguk University-Seoul, Seoul, South Korea
2Institute of Sport Science, Kangwon National University, Gangwon, South Korea
3Department of Sport Science, Korea Institute of Sport Science (KISS), Seoul, South Korea
4Department of Sport Science, Korea National Sport University, Seoul, South Korea
5School of Sport Science, University of Ulsan, Ulsan, South Korea
Author for correspondence: Joo-Ho Song; Department of Sport Science, Korea Institute of Sport Science (KISS), Seoul, South Korea; email: email@example.com
Background and Study Aim: Muscle fatigue and Golgi tendon organ laxity, which also, increases the threshold of muscle spindle discharge and disturbs afferent feedback. The purpose of this study was the effects of fatigue in lower extremities (quadriceps and hamstring) on H-reflex, M-wave, and Hmax/Mmax ratio changes in Korea National Team Taekwondo athletes.
Material and Methods: Twelve (7 male, 5 female) Korea National Team Taekwondo athletes were investigated. Participants completed 25 repetitions and 50 repetitions of fatigue protocol by using isokinetic dynamometer. The measured values of H-reflex and M-wave were collected simultaneously by electrical stimulation and the signals were amplified by the signal converter.
Results: Paired t-test showed that the 25 fatigue protocol and 50 fatigue protocol in minimum of knee extension and flexion showed a significant difference. However, no significant difference in 25 fatigue protocol and 50 fatigue protocol in maximum of knee extension and flexion. The changes of Hmax, Mmax and Hmax/Mmax ratio. There were no significant differences in Hmax, Mmax and Hmax/Mmax ratio.
Conclusions: Our fatigue protocols model increased local fatigued in the quadriceps and hamstring. However, Hmax and Hmax/Mmax ratio of the soleus muscles tend to decreased after the fatigue protocol but did not changed.
Key words: signal converter, M-wave, HRmax, H-reflex, electrical stimulation