KINEMATIC STUDY FOR ENHANCEMENT OF TECHNIQUE IN SKI JUMP
Grant-in-Aid for Scientific Research (C).
|Research Institution||HOKUSEIGAKUEN WOMEN'S JUNIOR COLLEGE|
SASAKI Tsutomu HOKUSEI WOMEN'S JR.COLLEGE,GENERAL EDUCATION,PROFESSOR, 一般教育, 教授 (40162375)
UCHIDA Eiji KOKUGAKUIN JR.COLLEGE,GENERAL EDUCATION,ASSOCIATED PROFESSOR, 一般教育, 助教授 (50213434)
|Project Fiscal Year
1994 – 1995
Completed(Fiscal Year 1995)
|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1995 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1994 : ¥900,000 (Direct Cost : ¥900,000)
|Keywords||SKI JUMPING / JOINT POWER / EMG / REACTION FORCE / VIDEO ANALYSIS / SEGMENT MODEL / JOINT ENERGY / スキージャンプ / 力学モデル / 関節パワー / 踏切動作 / 画像解析 / 運動様式 / 筋電図法|
The take-off motion in World class umpers were characterized using video analyzes and EMG analyzes. Jumping techniques were clasified three categories by joints power production. Relationship between joint power and muscle activities were analyzed by exponential regression analyzes. These research results are as follows :
1. Relationship between muscle activity and joint power
The muscles play a role in joint power generation. There was an exponential relation between joint power and the rEMG of the hip and knee muscles. Larger voltage production in a joint muscle indicates an increase in joint power. It follows that faster muscle contraction would be needed to generate larger joint power. The Gluteus maximus and Vastus medialis are major power producers in the hip and knee joints. However, for training related to joint power development, elastic lag should be considered in measurements of muscle activity shown by rEMG.
During jump action, when the single joint muscles produced the larges
t voltage, the joints produced the largest power with some lag time.
2. Classification of the take-off techniques
This study clarifies three important ski jumping techniques based on an analysis of the patterns of joint power production. Three techniques were named shuch as 1) the Phase Shift Power Generation Technique, 2) The Phase Shift and Leg Rotation Technique, and 3) the Close Power Generation Technique. The hip and knee joints play an important role for generating power and force in each jump technique. The manner of power generation is important for improving skills in each jumper. Characteristics in each technique are as follows :
1) The power production in each joint takes place in a regular order in the Phase Shift Power Generation Technique.
2) The Phase Shift and Leg Rotation Technique is characterized by forward rotational movement of the leg and phase resonance of the power generation pattern in the hip and knee joints.
3) The patterns of power generation in the knee and hip joint are produced without phase resonance in the Close Power Generation Tecnique.
Research Output (12results)