Looking at the thread again I am starting to think I may not be delivering exactly what you need. Anyway: http://www.crispquality.com/siberia/AlternateIKRig+JointHandle7.blend
Yeah, a better name would have been nice… Nonetheless, this is the rig I intend to update into my character. It provides complete detail in wrist, elbow and shoulder, and anything in between. I do not use armatures in the same way most do, so the shoulder, elbow and wrist are all actual objects; I tend to use hooks or similar ways to attach a skin mesh.
The wrist reacts to an armature IK target (called Wrist Target; it’s an Empty) to allow you to place the hand. Actually, the wrist is just copying the location and rotation of a ‘wrist proxy’. Decrease the Influence of the Copy Rotation (target: wrist proxy) whenever you need to rotate the hand freely. If you decrease the influence of the Copy Location constraint, the hand will fly off, though
Don’t mind the Armature.001. It was a necessity, to keep the elbow from flipping 90 degrees upwards when the arm stretched fully. Armature.001 has no other purpose (might seem like overkill, but it works quite well). Keep it and the Elbow Proxy invisible during rendering. In fact, keep everything invisible during rendering
The Elbow always tries to point towards an Empty called Elbow Target. this lets you control how the arm reaches for things; you can make it reach under a table or over a fence, just move the Elbow Target. Note that it can be a bit daunting to navigate the target in 3D through a 2D window, but you get used to it (I am still trying to make it more user-friendly).
And… the shoulder! It moves in the basic ways I have found a shoulder to move. I did look at actual anatomy to simulate it, but how things work and how things look may not always match. The outside ‘point’ of the shoulder objectbasically represents the deltoid; when the upper arm is pointed down (in relation to the torso), the deltoid points out. Moving the wrist high makes it point more and more upwards. And so on. If the movement of the shoulder is too drastic for you, turn up the Influence in the Shoulder object’s Copy Rotation (target: Shoulder Socket). The ‘deltoid’ will stay more in tune with the torso then, rather than with the upper arm. Play a little with it.
Oh, and yes, the torso can be turn, swivled, moved, etc, and the arm will (should) fit, shoulder adjusting to circumstances automatically. Just remember that the Elbow and Wrist Targets are seperate beings (though they can be parented to the torso, sacrificing some freedom but getting more predictability). If you do a lot of moving and rotating with the torso and leave the two targets, the arm will turn in inappropriate ways. Just move the two targets to where you want your hand (Wrist) and Elbow to point, and everything is happy.
Hope you enjoy. Please let me know of problems or ideas for improvements. I am still doing some clean-up and streamlining, too.