Generally you would do that kind of animation with inverse kinematics [IK]. I'll give you a scene file, but it's a bit of a complicated subject so you're probably best off reading the relevant help file sections.
Sorry I don't know any tutorials offhand, but the main thing to know is that you don't need joints to use IK. But it's helpful to look at what the joint tool produces. Namely, check out how the joints are aligned and where the axes are placed. You'll have to recreate that alignment/placement for your individual pieces, and then set them up in the same sort of hierarchy. Once you do that you can manually add IK tags, or do what I did and use the "character>commands>create IK Chain command.
To use the command, select the first and last "joints" (objects) in the chain and then run the command. It will automatically create the IK tag and the IK goal.
To use the command, select the first and last "joints" (objects) in the chain and then run the command. It will automatically create the IK tag and the IK goal."
Apparently this is going to take a bit more messing around on my part.
I've tried about 100x doing exactly what you said, but keep getting completely different result.
1. I make 6 total "cubes" for both upper and lower arm, grouping 3 cubes for each segment of arm.
2, I select the "shoulder" cube and end, would be "hand or wrist" cube, then use the Create IK Command and nothing happens.
When I try selecting the Null objects along with the "shoulder" and "wrist" I get more than 1 IK tag with messed up results.
This is very frustrating and the Help system doesn't help much on this one. It just says what you said.
Is there any way you can better explain in a similar step by step method to recreate what you did? Maybe something will click in my mind at some point!