Kontribusi Kekuatan Otot dan Fleksibilitas Sendi Terhadap Waktu Tempuh Renang 50 m Gaya Crawl = Contribution of the Muscle Strength and the Joint Flexibility toward the Time Taken for Swimming 50m by Crawl Stroke

ABSTRACT The swimming velocity, basically derives from the swimmer's capability to increase the propulsive force, to reducing the drag, or the combination for both of them. Therefore, it needs strong muscle and the flexibility of joints in the swimming sport. The strength is to increase the propulsive force and the flexibility is to maximize the use energy more efficiently and to reducing the drag. The results of this research are expected to be useful to improve the swimmer's achievement in Indonesia. The subjects of the research consist of 10, they are between 14 to 24 years old To find out the relationship between the muscle strength and the time The time taken for swimming 50 m by crawl stroke, it uses the linier regression analysis, while to find out the relationship between the muscle strength and the join flexibility with the time taken for swimming 50 m by crawl stroke, it uses double regression formulation. To find out the differenees of the time taken for swimming 50 m by crawl stroke, it is found the average of the time taken. The strength components and the joint flexibility which are influential on toward the time taken for swimming 50 m by crawl stroke are the strength of pull-arm muscle and push-arm muscle and the joint flexibility of shoulder flexi and plantar flexi. The effective contribution of the muscle strengthpull-arm and push-arm is 41,60 - 61,69%, and the joint flexibility of shoulder flex i and plantar flexi is 38,47% - 52,39%. Keywords: muscle strength -join flexibility�time taken for swimmin