FABRIK (Forward and Backward Reaching Inverse Kinematics) is quiet suitable for human inverse kinematics. I made a very basic FABRIK example, and the results is very interesting. There are many extended FABRIK features to look forward to. After loading .vcmx file, select blue plane then check “Track” to activate, no need to start simulation, try to move the box.
FABRIK.vcmx (190.2 KB)
That’s so cool! A couple of years ago I was also playing around with FABRIK but didn’t quite get it to work.
I wanted to test how this would work with the human resources in VC, and I got Otto’s hands moving in a short time.
Someone who’s better at linear algebra should implement this for real 
FABRIK_Otto.vcmx (1.9 MB)
FABRIK Otto can work with PM now.
A little trick makes it come true, it’s not perfect enough, but still fun to play with.
FABRIK Otto is attach to eCat Otto.
Show eCat Otto when walking and standing, hide FABRIK Otto.
Show FABRIK Otto when picking and placing, hide eCat Otto
Search "#!#" in eCat Otto "ResourceScript" for the modified script.
FABRIK Otto appearance can switch to Skeleton or Otto by "Show" property
Full demo video
https://youtu.be/-wLjAVbQCqs
Sample file
FABRIK_v1.1.vcmx (4.3 MB)