432 EP087 – Game specific demands on accelerations during change of direction movements: analysis of youth female soccer

Background Change of direction (COD) performance is an important discriminator of elite players in youth soccer and is also associated with common mechanisms of injury. Previous research has shown that the requirement for high-speed running, total distance and CODs are position specific, but little is known about the situational factors involved in COD maneuvers that could increase biomechanical demands during the final foot contact. Objective The objective of this study was to assess center of mass (COM) acceleration and movement during COD maneuvers during competitive soccer game to elucidate situation specific demands of COD performance. This information can assist in developing soccer-specific tests and training methods. Design Case-series. Setting One game was videorecorded with two cameras. Situational patterns were identified for each identified COD and included: ball possession (player/team), running speed (low/moderate or fast), body contact with other players during COD movement, turning side, and the angle of COD movement (90° cut/135° cut/180° pivot turn). Participants Fifteen U16–17 elite-level female youth soccer players were tracked with inertial measurement units attached on lower back. Interventions COD movements in combination with situational patterns were identified using high-speed video. Main outcome measures LASSO regression was used to identify the most important predictors related with higher vertical peak accelerations (PAv) of COM during COD movements. Results PAv in games was higher when with larger COD angles, increased running speed, or with contact when the player was challenged by the opposition. Conclusions This study adds to the literature of understanding the demands of COD performance in soccer match play. The unique approach with game-specific situational data of youth female players provides increased insight on the game-demands of COD and agility performance. A larger study including more games is warranted to increase confidence in using these variables as a basis for training or testing agility.