Greetings.
Recently, I read an internship report from Freark van der Kooi which is related sitting analysis.
I found that when muscle activity of a certain (group of) muscle(s) is plotted seriously high than other muscle, we can modify the stiffness of the related joints and fixed the over-estimated muscle activities.
In this report, the author found that the activation of Psoas Major was strangely high, changed the lumbar spine joint’s stiffness and retrieved the appropriate muscle activity.
Now, one of my analysis model sometimes have a sudden increase of muscle activity - one not related with the motion’s mainly activated muscle - with a short frame ranges.
I want to see check those stiffness parameters just in case, but I cannot find where the stiffness of a joint is defined in AMMRV1.3 human model.
Actually, I am inherited with not finding something 
I searched this forum and found a way to add stiffness into a joint by AnyFunInterpol which was posted in wiki.
http://forum.anyscript.org/showthread.php?t=2724
But one thing I want to know is not just adding stiffness of a joint but seeing the joint stiffness in current model.
Where I can find out?