I have been reading a number of papers on the biomechanics of running and they all talk about the center of mass (COM), but I haven't found any description of how to determine the center of mass. I understand, for instance, that the center of mass moves forward with more forward lean. The reason I need to be able to determine the center of mass is to measure the amount of overstride. Overstride is defined as the distance from the COM to the point of initial foot contact. Any help very much appreciated.