title: Contribution of hand and foot force to take-off velocity for the kick-start in competitive swimming.
abstract: This study examines the hand and foot reaction force recorded independently while performing the kick-start technique. Eleven male competitive swimmers performed three trials for the kick-start with maximum effort. Three force platforms (main block, backplate and handgrip) were used to measure reaction forces during starting motion. Force impulses from the hands, front foot and rearfoot were calculated via time integration. During the kick-start, the vertical impulse from the front foot was significantly higher than that from the rearfoot and the horizontal impulse from the rearfoot was significantly higher than that from the front foot. The force impulse from the front foot was dominant for generating vertical take-off velocity and the force impulse from the rearfoot was dominant for horizontal take-off velocity. The kick-start's shorter block time in comparison to prior measurements of the grab start was explained by the development of horizontal reaction force from the hands and the rearfoot at the beginning of the starting motion.
authors.affiliation: a School of Health and Sports Science , Juntendo University , Inzai , Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takeda
authors.affiliation: b Graduate School of Comprehensive Human Sciences , University of Tsukuba , Tsukuba , Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Sakai
authors.affiliation: c Faculty of Health and Sport Sciences , University of Tsukuba , Tsukuba , Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Takagi
authors.affiliation: d School of Sport Sciences , Waseda University , Tokorozawa , Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Okuno
authors.affiliation: c Faculty of Health and Sport Sciences , University of Tsukuba , Tsukuba , Japan.
authors.forename: Shozo
authors.initials: S
authors.lastname: Tsubakimoto
mesh_terms: D000054:Acceleration; D000293:Adolescent; D000328:Adult; D003163:Competitive Behavior / Q000502:physiology; D005528:Foot / Q000502:physiology*; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement; D013550:Swimming / Q000502:physiology*; D055815:Young Adult
keywords: Block-time; jump; reaction force; take-off velocity