There are many kinds of waddle/spreader pants out there, and yes- many of the best come from Über-kinky Germany.
What are they? basically some sort of clothing that increases the bulk between your legs, or spreads your legs apart, forcing you to waddle (if you can), or be forced to crawl. It seems like there are 3 major syles.
1. Padded crotch- a pull-on diaper cover, sometimes in form of a onesie or overalls, with very thick padding in the crotch. Great for people who love a huge, obvious diaper. Not substantial enough to actually "force" you to waddle. (A similar effect can be achieved by just wearing more layers
2. Spreader sheet- a pull-on diaper cover, sometimes in form of a onesie or overalls, with very a sheet of rigid material in the crotch- like a rectangular diaper-stuffer, except made from firm plastic. If the plastic is thick/strong enough, it is literally impossible to bring your legs together- forcing you to waddle. The downside is that it's very uncomfortable, and kind of unnatural looking . . .
3. "Spreader pants/harness"- a body harness that (relatively comfortably) forces your legs apart, making waddling difficult, and typically reducing the person wearing them to give up and crawl. I've seen a couple of crappy imitations, but here is a link to the real thing: http://www.adultbaby-shop.com/shop/en/Special-spreader-pants (fyi: I dunno if this link is a re-seller, or the original producer with a modernized storefront). I reaally want one of these!!
Log onto Ebay and SEARCH "Spreading Diaper".
The main source is a seller in Hungary - prices are reasonable - the shipping is the killing factor - but looks and ideas are FREE !
Starting with simple waddle walking to impaired and crawling and then in one heavy application if one is on one's back you become
almost turtle like and can not roll over let alone crawl away. Even more exciting when wearing padded mittens and escape becomes
a challenge for the Houdini in yourself !
Knock yourself out !