Research on reverse side keyboards?

[Nzen]

Watched TrewGrip's kickstarter sputter and wondered if there has been research on the ergonomics of keyboards with keys on the reverse side.

Trewgrip would have been a tenkey sized, curved surface with keys on the side opposite the user. One can thereby type while holding the keyboard. Trewgrip's originators hyped it for mobile devices, as a phone or tablet could fit on the side facing the typist. The 250 dollar model would communicate via bluetooth, and offered a bundle with a bluetooth dongle for 100 dollars more. With the bundle or a third party dongle it would have been capable of communicating with traditional computers as well.

But, the campaign only attracted 1.6e4 of 1e5 dollars. It will shutter as did Talons, a week or two ago. So, have there have been similar products of this style, or even just some ergonomic research on the efficacy of typing on the reverse surface of a keyboard? My kinesis freestyle just lost a row of keys, so I'm in the market for a new board. (Typing on hp knockoff, wondering if I should remap tenkey to "jkl;" row via autohotkey.) Ergodox is quite exciting  - or ergoGP if I wait longer, but this paradigm could offer better posture.

(edited to proper markdown)

[tp4tissue]

problem is with controllers, you need the fingers to hold to it.  if your fingers are typing underneath, all the fingers you're not using must be for support.  this is a huge waste of effort...

also having your hands that far apart while twisting your wrist to match the horizontal curve... no go..

[divito]

It's a clever approach to the idea and problem, but doesn't quite get there. And taking a look at their page, they probably will not meet their goal either.

[Findecanor]

The idea is not entirely new. I have seen different other "backtyping" keyboards some of which have been only prototypes:
* The AlphaUI, is the one that comes the closest to this keyboard, and seems to be a whole lot more developed and polished.
* The RearType from Microsoft's research-division. (they make lots of things that never find their way to production)
* The Grippity.
* The gamepad-shaped Alphagrip has some letters on the front.

... and I am sure that I have seen more. I remember one that showed a representation of the fingers on the front screen.

Other keyboards with similar ideas:
* Typing with both hands, without seeing the keys, you can do on the Safetype.
* For one-handed chorded typing, there is the Twiddler, which has been around for decades if I am not mistaken. Even though it is one-handed, it is supposed to be held the same.