update_bvh.py is a command line program which can apply changes to a pose in a .bvh file, creating a new .bvh file with the altered pose. update_bvh.py reads directive files which specify changes to the X-, Y-, or Z- rotation or position parameters for the joints controlled by the .bvh file. By running a text editor to comose the changes, a terminal to run the program, and Makehuman to test the results, you can generate a new pose fairly quickly. This .zip file contains the update_bvh.py file and a .html file with instructions. HTH.