THE BLOMECHANICAL EFFECTS OF ANTICIPATION DURING A STOP-&-BACK RUN TASK TO SCREEN HIGHRISK ATHLETES FOR NONCONTACT ACL INJURY

Abstract

The purpose of this study was to determine the role of anticipation on the lower extremity and trunk kinematics, and the height of the center of mass during a stop-&-back run task. Collegiate athletes (n=18) were recruited and completed three tasks; anticipated stop, unanticipated stop, and anticipated stop with a badminton net in front of their face. Three video cameras were used, and the trunk and extremity kinematics, and the height of center of mass (COM) for the second step before the complete stop (deceleration step) and the step of the complete stop (stopping step) were analyzed. At the initial contact of the deceleration step, the height of the COM was greater and the knee position was more posterior in the unanticipated condition than the other two conditions (p less than .05). The results showed the height of the COM was higher during unanticipated stop-&-back run task, which has important implications for future ACL injury screening.