anything is possible with programing!
besides it actually wouldn't be that hard, all one would need is additional sets of skeletal animations and some scripting.
if health = >90% 
   use "walk_animation_normal"
if health = <90% and >60%
   use "Walk_animation_limp"
if health = <60% and >40%
   use "walk_animation_stumble"
if health = <40% and >0%
   use "walk_animation_crawl"
( pardon my crappy example of scripting )			hay, "OC" ..... i got something for ya right here!   _|_ (^.^) _|_

"MMO-RPG" = "Mass Market Oriented - Repetitive Profit Genera" 
- damned things still svcked me in ...