“I knew rigging my Moosah and Chub model would be quite the project, but once I understood some of Softimage XSI’s rigging features it went pretty smooth. For this model I created a whole series of soft constraints, which can give the effect of secondary action, gravity, wind resistance, etc..”
http://www.3dtotal.com/team/Tutorials_3/rigging_for_moosah_and_chub/rigging_for_moosah_and_chub01.php