Ahh, you're right. There IS a significant improvement between the last piece and this. Much better as far as anatomy is concerned. Much better feet. Buckles and restraints are a lot better than the last one. You might still want to consider widening the chains a little and giving them more substance. Just thickening the lines will suffice.
This is a LOT better than the other image. I'm glad you dropped the flat "straight on" view for something with more depth. Torso shapeliness is definitely better than the last drawing, though the arms and legs still need work with their shapes and sizes. (Keep in mind that there is arm length underneath the restraint, to be factored into where to place elbows, et cetera.) Better proportion with the hands in relation to the forearms. You should even out where the fingers meet the hands - the space between index and middle seems to be deeper and better-constructed than the spaces between the other fingers. Face is a definite improvement. The last one had a lopsided triangularish effect going on. This one is much nicer, and the curves of the jawline are a lot better.
Overall, very big improvement over the last image. Keep at it. I still recommend looking into taking a figure drawing class, if possible, or just drawing nude pictures from the internet. I also still strongly suggest drawing things in real life to give you a basis for overall technique. Granted, I know you're going for a cartoon look, but all of the animators, cartoonists, illustrators, et cetera with whom I've spoken have said the same thing: practice drawing real things first. It really does help, I assure you.
Keep in mind that all of this commentary is done in the interest of helping you. I by no means want to discourage you in any way. I know it's easier to be a critic than one who is criticized, but trust me, I have no reason to do this other than to try to help you. I have nothing to gain by your failure. (Of course, I guess you can argue I have nothing to gain by your success, either, but I guess you'll just have to take my word for it.) If you're thinking I'm being harsh because of some psychological need to make others feel bad to make myself feel superior, there are much better ways for me to vent my own insecurities and feelings of artistic inadequacy than trolling fetish messageboards to pick apart people's drawings. The reason I'm harsh is because sugarcoating is a half-truth that will produce nothing but half-reactions. Holding back may spare your feelings, but all that means is that you were emotionally protected by a lie.