By drawing the head, rib cage, hips and joints before adding the body as a whole, you'll find that your anatomy will improve. Right now it's still a little choppy in some places and I feel it might be because you're not quite yet fully understand how to connect the parts to one another. By breaking the body down into basic shapes, you'll gain a better understanding of the body!
If you're doing 30 second gestures, don't worry too much about making it look 'neat' or complete. If you only get the basic shapes down that's plenty!
Starting from 1-2 minutes and up, you get to build on top of these basic shapes and you'll see a drastic improvement. Give it a shot and let us know how it goes?