You can choose from basic poses in MakeHuman.
If you want to pose the person yourself, then give the person a skeleton.
Here’s a tutorial on importing Makehuman models into Blender. It’s pretty complicated, but it’ll work if you follow the steps.
http://www.makehumancommunity.org/wiki/Moving_Assets_into_Blender#Importing_a_MakeHuman_Collada_File
Then you can pose the person in Blender & finally import into SketchUp.
Blender shortcuts:
