Just realized the human's probably there as a size reference huh. :) The motion does seem a bit choppier in this one, maybe just not the same amount of frames, but otherwise it's not bad... can't really think of anything to improve with these. It might be easier to suggest something on a human cycle where you understand the anatomy a bit more/how we function and look while we do...
This looks good too. Maybe the neck's a bit stiff? Maybe that...
-cd-