Like I said in the last topic regarding climbing ladders, you need to use skeletal animation to do that. It is available to certain modified Q3 Engines, its called MD4, but its disabled by default and only a few games really used it. ET uses MD3
per vertex animation which means animation that compares to that video will take the animators to the
nut house. On the other hand, ET also has these formats called MDM and MDX, but I dont think those two are really useful because the only existing plugins for the bone structure available is for 3dSMax r3, which we all should know by now is nolonger available anywhere. Even if it is, it would be hard to find and get even through p2p with the lack of sources.
For further reading on the MD4 goto
http://gongo.quakedev.com/md4.html and for the Quake 3 Engine GPL version
http://en.wikipedia.org/wiki/Quake_3_engine
and the Id Software FTP website with the GPLed engine
ftp://ftp.idsoftware.com/idstuff/source/