vertical jump height is a method of assessing muscle strength and power in the lower body, and is used to assess athletic ability. the gold standard in measuring vertical jump height is the measurement of the vertical centre of mass (com) displacement from three-dimensional (3d) video analysis. vertical jump height is ultimately affected by takeoff com velocity, as greater takeoff velocity results in greater jump height. the current study explored the use of takeoff versus maximum com velocity by examining the relationships and differences between 3d video analysis and 3d force platform analysis when predicting vertical com displacement. use of the vertec, and correction of takeoff com velocity using takeoff posiion, was explored through methods proposed by aragon-vargas (2000) and moir (2008).