title: Functional Role of the Front and Back Legs During a Track Start with Special Reference to an Inverted Pendulum Model in College Swimmers.
abstract: This study investigated factors that determine the velocity of the center of mass (CM) and flight distance from a track start to devise effective technical and physical training methods. Nine male and 5 female competitive swimmers participated in this study. Kinematics and ground reaction forces of the front and back legs were recorded using a video camera and force plates. The track start was modeled as an inverted pendulum system including a compliant leg, connecting the CM and front edge of the starting block. The increase in the horizontal velocity of the CM immediately after the start signal was closely correlated with the rotational component of the inverted pendulum. This rotational component at hands-off was significantly correlated with the average vertical force of the back plate from the start signal to hands-off (r = .967, P < .001). The flight distance / height was significantly correlated with the average vertical force of the front plate from the back foot-off to front foot-off (r = .783, P < .01). The results indicate that the legs on the starting block in the track start play a different role in the behavior of the inverted pendulum.
authors.affiliation: 1 Niigata University of Health and Welfare.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ikeda
authors.affiliation: 1 Niigata University of Health and Welfare.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ichikawa
authors.affiliation: 1 Niigata University of Health and Welfare.
authors.forename: Rio
authors.initials: R
authors.lastname: Nara
authors.affiliation: 1 Niigata University of Health and Welfare.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Baba
authors.affiliation: 1 Niigata University of Health and Welfare.
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Shimoyama
authors.affiliation: 2 Japan Institute of Sports Sciences.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kubo
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D001696:Biomechanical Phenomena; D003163:Competitive Behavior; D005260:Female; D006801:Humans; D007564:Japan; D007866:Leg / Q000502:physiology*; D008297:Male; D013550:Swimming / Q000502:physiology*; D013647:Task Performance and Analysis; D055815:Young Adult
keywords: biomechanics; force platform; swimming; velocity