IDENTIFICATION OF INSTANTS OF TOUCHDOWN AND TAKE-OFF IN SPRINT RUNNING USING AN AUTOMATIC MOTION ANALYSIS SYSTEM

Abstract

The identification of the instants of touchdown and take-off are important in determining step characteristics during the biomechanical analysis of sprinting. Six athletes performed 20 sprint trials each in which a single foot contact was made with a force plate, and kinematic data were gathered with five toe markers. Criterion event times taken from the force plate were compared to event times calculated using vertical displacement thresholds from standing trials and peak vertical acceleration values. The lowest RMS differences between the criterion value and the standing trial thresholds were between 0.003 and 0.005 s, whilst the lowest RMS differences for vertical acceleration ranged between 0.005 and 0.007 s. These results revealed that accurate touchdown and take-off events in sprinting could be determined using an automatic motion analysis system.