Your pose overall looks very stiff and uncomfortable. What I suggest doing is looking at reference images of people standing in both neutral positions as well as a defensive stance with the key leg back slightly for support. Usually what I do before I ever move to pixel art is draw it out in a sketch to get the pose I want as well as the proportions, it makes the translation to pixel format much easier and, if you animate using a sketched animatic, you'll get a lot better quality animation to boot.