Don't laugh. It's a quick sketch. Not to scale. Just to convey to my wife what I was thinking at the time.
Now. This was built with 3/4" PVC to give it stability because the fabric I used for the costume was waaaaaay heavy. Hindsight being 20/20 and all, I would have used a lighter fabric. My thinking is you could use football pads and a backpack frame and use much less pvc than I did. But, I haven't tried putting it into practice. The front piece that spans the waist is good for leaning over as it prevents the costume from falling off you. So, if you get rid of it, you'll need a belt going around you to keep it from falling off. Here's a pic of the finished product
My mother in law is 5' and not overweight just to give you an idea of scale.