Depends on what you want to do.

• You can go dynamic
• You can go Bullet physics in the latest Poser versions
• You can use the morph brush
• You can use magnets to deform
• You can create "handles" in Poser11
• You can take original obj file in a 3D app and "defom" as required => (never - ever use an obj exported from Poser. That simply does not work, because vertex order gets lost)
• Any combination from the above.

Hundreds of options but all depend on what exactly you want to do.