in multiplayer and free play when i hold my body and i do a move it only lets me do extend and contract like other people when they hold they can also relax at the same time does any body know how to fix it ?

I usually hover the mouse over the joint I want to relax and then hit the 'X' button. Also, you can left-click on the joints and make them relax.

Press Esc -> Click Options -> Click Setup -> Set Mouse Buttons to 1

That should fix it. :P