2020, Volume 16
Influence of fatigue on head angular acceleration in judo high-intensity exercise
Yoshihisa Ishikawa1, Kenji Anata2, Hironori Hayashi3, Naoya Uchimura4, Shuichi Okada5
1Faculty of Education, Osaka Kyoiku University, Kashiwara, Japan
2Graduate School of Doctoral Programme Human Development and Environment, Kobe University, Kobe , Japan
3Department of Sport, Faculty of Sport Study, Biwako Seikei Sport College, Seikei , Japan
4Faculty of Sport and Health Sciences, Osaka Sangyo University, Sangyo , Japan
5Graduate School of Human Development and Environment, Kobe University, Kobe , Japan
Author for correspondence: Yoshihisa Ishikawa; Faculty of Education, Osaka Kyoiku University, Kashiwara, Japan; email: firstname.lastname@example.org
Background and Study Aim: Head injuries have become a serious problem in judo. For people to safely enjoy judo and with peace of mind, it is important to clarify the causes of head injury and undertake safety measures. The cognitive purpose of this study is the effects of high-intensity exercise fatigue on the angular acceleration of the head in judo.
Material and Methods: We included 15 male members of a university judo club. For high-intensity exercise, seoi-nage was performed once every 2.5 seconds. An angular velocity sensor was used to calculate the angular acceleration of the subjects’ heads (200 Hz).
Results: The maximum angular acceleration of the head immediately increased after high-intensity exercise (p<0.01). The forward flexion muscle strength of the neck increased (p<0.05) and the strength of posterior flexion did not change.
Conclusions: Although the neck muscle strength was not reduced by high-intensity exercise, the maximum angular acceleration of the head increased, it may be related to the slow response of the neck muscle strength that is associated with head injury. Future safety measures should take into account that it is not enough to strengthen the neck muscle alone. Taking appropriate rest during exercise and not performing throwing exercises after high-intensity exercise will reduce the risk of head injury.
Key words: Accident Prevention, Heart Rate, osoto-gari, Muscle strength