I guess I should have added (and it may have been mentioned previously in this thread)is that that the COM is lower on the ascending slope of the parabola (because of the inward lean, etc.) when the parabolic flight is initiated at take off than on touchdown. On touchdown, the athlete is in a much more vertical (tall) posture – with the lead leg fully extended (give or take) – with the foot often plantar-flexed – which means the COM is higher on the descending slope of the parabola at touchdown.
Also – studies (McDonald) have shown that the COM continues to drop through out the first step well into the 2nd step – where the COM finally begins to rise again.
Makes you re-think/re-visualize the parabolic flight…KM