Some of us with heavy upper bodies, and probably the rest of you as well, find biking quite strenuous on the wrists. I see people all the time shaking their wrists to restore circulation, changing grips every few minutes to avoid the strain and the pain.
The normal way handlebars are gripped bends the wrist and causes strain.
For longer rides, we often try grips like the following to more directly put the weight on the arm and the shoulders, rather than on the wrist.
It's very easy to relax from such a grip and fall back on the normal grip, though.
This is where the Wrist Saver comes in. It could come with 1 or 2 main brace locations.
The most natural position would be accomplished by a small ridge under a wrist guard, something like the Rollerblade® wrist guards used for in-line skating.
The ridge could be placed either close to the wrist or slightly up the arm.
It would also be possible to extend the wrist guard and allow supporting the arm directly on the handlbars, bypassing the wrist and hands:
The Wrist Savers could look something like this (note the sketched-in black ridge and knuckle bridge):
See it on HalfBakery.com