ABSTRACT
Research into locomotion has tended to focus on linear motion, such as straight treadmill or overground running, with only limited data on non-linear motion that would be used in soccer play (Hamill et al., 1987; Smith et al., 1997). Due to the open skilled nature of soccer performance, these non-linear actions are situation specific and rarely replicated, in terms of speed, distance, severity or intensity. Thus, standardisation is difficult and problematic for appropriate investigation. Smith et al. (1997) highlighted non-linear motion in the form of curvilinear running (motion along a constant grade of curvature), at a range of radii of 5 m to 15 m during soccer play. The ability to perform and maintain curved motion and perform overlapping runs or channelled runs along the defensive line to remain onside are essential components of the game. With the performance of non-linear motion so inherent in the game of soccer, biomechanical analysis of non-linear motion would aid further understanding of the mechanisms involved in performance of these movements.
