ABSTRACT
Football is characterized by short, abrupt and dynamic, non-cyclic movements like accelerations, decelerations and changes of directions (Ekblom, 1986). FIFA (2009) reported that general changes of running velocity and running directions occur every 4–6 seconds during a football game. Changes of direction can be categorized as cutting movements (0–90° relative to original running direction) or turning movements (90–180° relative to original running direction). Dynamic changes of directions are very common in football and occur in numerous game situations. Unanticipated turning movements (UA) especially occur during rapid transitions from offensive to defensive playing situations, when reacting to opponent's movement paths as well as when reacting to sudden or unexpected ball passes. Preplanned turning movements (PP) are predominantly used for feints within or without ball. Generally, all actions during a football game are either preplanned or unanticipated movements. Thereby preplanned movements mark active actions of a player based on his personal performance plan. Unanticipated movements mark reactive actions triggered by the specific performance of opponents or other elements of the game situation like passes or turnovers. Thus, a large percentage of all defensive actions can be described as unanticipated movements.
