Animation looks weird ingame, but in maya everything is OK

[Chefchen]

So i switched from Blender to Maya to animate stuff.
This time i actually was able to bring an animation into the game which has been played.
The only Problem is, that the animation is Played weird ingame...
Thats how it looks in Maya:

And thats how it looks in Ingame:

You can see, that this is almost the same animation. ...well kinda...
Does anyone Know what Causes this, and how i can fix it?
This animation has been created using rigs of "viewmodel_base_viewhands" aka "viewhands_usmc3"