Problem Exporting Blender animation

I have the following situation.
I have a fbx file wich I intend to use in a academic project.
I’m using assimp to load skeletal animations.
When I export my fbx with the animations I made, I see that the rotations are all wrong, the bone is rotating arround the global origin instead of local origin .
Here is the original file :

Here’s the animation I made:

Here’s what I get after exporting the animated file.