Absolute position of bones


I use make human and the Mocap tool to animate characters in Blender. I happen to need the absolute position of the bone for the entire animation. I would like to export them in a text file for example.
All of this is for computer vision research purposes.
It is possible to calculate the motion paths of those bones and visualize them but I cannot figure out how to access this information using the Python API for example.

Does anybody have a solution ?

Thanks in advance !