title: Biomechanical Analysis of Defensive Cutting Actions During Game Situations: Six Cases in Collegiate Soccer Competitions.
abstract: The strengths of interpersonal dyads formed by the attacker and defender in one-on-one situations are crucial for performance in team ball sports such as soccer. The purpose of this study was to analyze the kinematics of one-on-one defensive movements in soccer competitions, and determine the relationships between lower limb kinematics and the center of mass translation during cutting actions. Six defensive scenes in which a player was responding to an offender's dribble attack were selected for analysis. To reconstruct the three-dimensional kinematics of the players, we used a photogrammetric model-based image-matching technique. The hip and knee kinematics were calculated from the matched skeleton model. In addition, the center of mass height was expressed as a ratio of each participant's body height. The relationships between the center of mass height and the kinematics were determined by the Pearson's product-moment correlation coefficient. The normalized center of mass height at initial contact was correlated with the vertical center of mass displacement (r = 0.832, p = 0.040) and hip flexion angle at initial contact (r = -0.823, p = 0.044). This suggests that the lower center of mass at initial contact is an important factor to reduce the downwards vertical center of mass translation during defensive cutting actions, and that this is executed primarily through hip flexion. It is therefore recommended that players land with an adequately flexed hip at initial contact during one-on-one cutting actions to minimize the vertical center of mass excursion.
authors.affiliation: Faculty of Health Sciences, Tokyo Ariake University of Medical and Health Sciences, Tokyo, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Sasaki
authors.affiliation: Department of Joint Surgery and Sports Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Koga
authors.affiliation: Oslo Sports Trauma Research Center, Norwegian School of Sport Sciences, Oslo, Norway.
authors.forename: Tron
authors.initials: T
authors.lastname: Krosshaug
authors.affiliation: Graduate School of Sport Sciences, Waseda University, Saitama, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kaneko
authors.affiliation: Faculty of Sport Sciences, Waseda University, Saitama, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Fukubayashi
keywords: Video analysis; center of mass; defender; kinematics; performance