here is a video of Ikeda sensei talking about using breathing to aid your movement
http://www.youtube.com/watch?v=4hB-knlRDZ8 using close and open body through breath
or this one
http://www.youtube.com/watch?v=St7I0M2fx1c for dantien/hara movement
or this one
http://www.youtube.com/watch?v=0K3a9Z5DZnc - which sort of an SJT (stupid jin trick) where jin does not depend on structure. demo, not necessary training.
or this
http://www.youtube.com/watch?v=epfWXEuEgYI - sort of basic "four-legged animal" and i am the control end. demo, not necessary training.
cross reference this
http://www.youtube.com/watch?v=SP9FoeyLjDo with the aiki-taiso exercises
first movement is similar to open-close body to Ikeda video (tekubikosa and johokosa undo)
second movement - funakogi undo
third movement - ikkyo undo
fourth - sayu undo
problem is video won't show you what all the gazillion things going on inside the person body that the person is focus his/her intention on.