
Looking to understand about walking animation and the math of it;
basically simulating how the body moves in opposing tandem, and the how the pelvis, spines ribs,heads orients/rotate, and displace againsts/following the dominant walking appendage; All numbers and physics operation that help it poses in cycles, maybe of a second or two loops(12-24frames persecond). A correct simulation basis is important but not just mocap data since that does not work for various different situations.
Books, links or video are welcome
(Edited 1 minute later.)

Something like this schematics, but also involves various things like weight, speed, conditions which will manipulates the postures and patterns.... and then maybe with obstacles and uneven surfaces; how the locomotion modulates against them.
The subject in question too shouldnt involve more than the bones; muscles motoric can come laters.