I saw this picture in my recently received USA Diving magazine. What an amazing pike position! This is interesting biomechanically, for two reasons;
1) Moment of Inertia – I recently discussed how to make a somersault spin rapidly and here is the picture perfect example. I don’t think a pike could be any tighter and for him, his moment of inertia is as small as he is capable of making it, (while still in a proper pike position). This will allow him to spin at his maximum rate for the amount of angular momentum that he created off the board.
2) Hip hinge – notice how he is hinged at the hip. His chest and stomach are flat on his legs with minimal rounding of the back. This requires excellent flexibility.