Nowadays high jumpers clear the rod keeping their center of mass at minimum possible height in order to put less effort. To do this they bend their body in a semicircular shape above the bar as shown in the figure below.
As we know the center of the mass of a uniform semicircular wire is at r-2r/π = (π-2)r/π = 0.36 r below its crest. So the center of mass may cross below the bar during the successful clearance of the bar as shown in the figure.
