Curious Detail during this F-22A Raptor Video

Hi all

Please, check this F-22A’s Video at Reno Air Races 2008:

http://www.youtube.com/watch?v=Al95wdRYrp8

and note that starting at 5:20 when Paul “Max” Moga is getting ready to shut his plane down, the ground crew puts a wood plate (or something else) under the F-22A’s main gear but none under the nose gear. Any ideas why this has been done? Why to put wood plates under a fighter’s gear so it can park?

Thanks in advance