The video presentation by Esther Gokhale explains how a forward-tipped pelvis is the natural position for the pelvis. This is in contrast to many "posture experts" who claim that a flat or neutral pelvis is ideal. This mistaken idea has even spread to running, where many programs such as ChiRunning specify that the pelvis should be flat.
Watching some college football games yesterday, it's very obvious that most if not all the athletes have a forward-tipped pelvis. This seems especially true for those in speed positions like wide receiver and running back. Even in mid-air this is apparent, as shown below.