How can I calculate the relative motion from the ASCII raw marker data (i.e XYZ coordinates)?

I am working on VICON software. I need to find out the relative motion of the women's belly. All what Vicon gives me is the raw coordinates data in X,Y, and Z axis. I was wondering if there is a software, matLab code, or Body Builder program that can calculate the (range of motion, Joint angles, Velocity,....etc)??

Thank you