THE APPLICATION OF A SPORT-SPECIFIC 3D STEREOSCOPIC STIMULUS TO EXAMINE PRE-PLANNING TIME AND GAZE CHARACTERISTICS DURING EVASIVE SIDE-STEPPING MANOEUVRES

Abstract

It is well established that anterior cruciate ligament (ACL) injuries are serious, debilitating and costly for an individual, while also creating a significant public health burden at a societal level. ACL injuries occur when inappropriate external loads are applied to the knee and most commonly occur during the performance of a side-stepping (Ssg) manoeuvre (Besier et al., 2001a). Previous laboratory based investigations of evasive Ssg have employed generic light or mannequin visual stimuli in an effort to simulate the time and space constraints experienced by athletes, in the preparation and execution of the Ssg manoeuvre (Besier et al., 2001b; Besier et al., 2003; Mclean et al., 2004). However, a possible outcome of attempts to impose these constraints in lab environments is that the use of unrealistic visual stimuli may not accurately reflect or identify the relationship of the perceptual demands of the task with injury risk variables, during a sidestep in game based situations. This study proposes that the presentation of a three dimensional (3D) stereoscopic stimulus (3DSS), featuring a 3D video based sport specific reconstruction of an opposing defender(s) simulating a tackle, may improve the ecological validity of laboratory based investigations. Additionally, the incorporation of the 3DSS tool with eye tracking will allow for the subject’s gaze characteristics (fixations, durations on the 3DSS image) to be assessed. The general aims of this study were to: Technical • develop a 3DSS that delivers realistic sport-specific constraints to footballers during evasive Ssg manoeuvres, • create 3DSS scenarios that incorporate realistic game based variations of imposed time and space constraints (e.g. 3DSS tackle scenarios with one or two defenders), • develop an interface and protocol that integrates the 3DSS system with a commercial eye tracking system (ASL Eye Tracking Recorder), for the purpose of quantifying the lab based subject’s gaze characteristics on the projected stimulus during a Ssg manoeuvre, Experimental • identify differences in biomechanical variables (kinematic, kinetic and neuromuscular) associated with increased injury risk during Ssg manoeuvres, using a traditional light (light emitting diode) based stimulus (LBSS) compared with a 3DSS stimuli.