Journal of Sports Science and Medicine
Journal of Sports Science and Medicine
ISSN: 1303 - 2968   
Ios-APP Journal of Sports Science and Medicine
Androit-APP Journal of Sports Science and Medicine
Views
7688
Download
153
from September 2014
 
©Journal of Sports Science and Medicine (2007) 06, 15 - 22

Combat Sports Special Issue 2, Research article
A Kinematic Comparison of the Judo Throw Harai-Goshi during Competitive and Non-Competitive Conditions
Rodney Imamura1, , Misaki Iteya2, Alan Hreljac1, Rafael Escamilla1
Author Information
1 California State University Sacramento, Department of Kinesiology and Health Science, Sacramento, CA, USA
2 Tokyo Gakugei University, Japan

Rodney Imamura
✉ California State University Sacramento, Department of Kinesiology and Health Science, 6000 J Street, Sacramento, CA 95819-6073, USA
Email: rimamura@csus.edu
Publish Date
Received: 25-01-2007
Accepted: 26-07-2007
Published (online): 01-10-2007
Share this article
 
 
ABSTRACT

The purpose of this study was to compare the kinematics of kuzushi/tsukuri (KT) phases of the harai-goshi throw under competitive and non-competitive conditions. A third degree black belt subject served as the tori (thrower) for both conditions. Two black belt participants ranked as first degree and fourth degree served as the uke (faller) for the competitive and non-competitive conditions, respectively. Two video cameras (JVC 60 Hz) and a three dimensional motion analysis system (Vicon-Peak Performance Technologies, Inc., Englewood, CO) were used to collect and analyze peak velocity for the center of mass (COM) of uke and tori and peak angular velocity of tori’s trunk (TAV). Data were smoothed using a 4th order zero lag Butterworth filter with a cut-off frequency set by the Peak software optimization technique. All variables were normalized by time as a percentage of the KT phase. In general, the COM directional velocity patterns were similar between conditions. Uke’s defensive efforts during the competitive condition created differences in timing and magnitude of peak COM and TAV velocities. During competition, tori created larger peak COM velocities onto uke which indicated greater throwing power. Peak velocities for tori’s COM were larger during the non-competitive condition since uke’s resistance was minimal. Findings of the competitive condition suggested that mediolateral COM movement towards tori’s pulling (left) hand can be an ideal set-up movement prior to execution. Tori’s TAV was also greater during the competitive condition. Two distinct TAVs were observed, a counterclockwise TAV created by tori turning their hips during the entrance of the throw and a clockwise TAV created by the shoulders turning to complete the 180 degree body turn with the simultaneous leg sweep. It is thought that the counterclockwise rotation aids in producing a pre-stretch of trunk muscles which helps to create greater trunk rotation power.

Key words: Biomechanics, Harai-goshi, kinematics, judo, throw, velocity


           Key Points
  • COM directional velocity patterns were similar between conditions and were consistent with the findings from previous kinetic studies.
  • Uke’s defensive efforts during the competitive condition created differences in timing and magnitude of peak COM and TAV velocities.
  • Mediolateral COM movement towards tori’s pulling (left) hand can be an ideal set-up movement prior to execuation.
  • It is thought that the counterclockwise rotation aids in producing a pre-stretch of trunk muscles which helps to create greater trunk rotation power.
 
 
Home Issues About Authors
Contact Current Editorial board Authors instructions
Email alerts In Press Mission For Reviewers
Archive Scope
Supplements Statistics
Most Read Articles
  Most Cited Articles
 
  
 
JSSM | Copyright 2001-2020 | All rights reserved. | LEGAL NOTICES | Publisher

It is forbidden the total or partial reproduction of this web site and the published materials, the treatment of its database, any kind of transition and for any means, either electronic, mechanic or other methods, without the previous written permission of the JSSM.

This work is licensed under a Creative Commons License Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.