FK Arms

When it comes to doing arms without any IK, does anyone have any tips as far as simulating joint rotation limits?

After I have my characters arms up the air, the joints tend to rotate the arm backwards instead of bringing them down properly.

Here are some visuals. I think I need some help with how Blender tweens fk.

Watch the left arm

I start here:

and end here:

When I scrub I see that the Left arm is rotating backwards to get into that final pose.

I thought I could just add an inbetween key to help explain to Blender which way I wanted to rotate that arm

The problem is, after I do that, when I scrub to the next frame the arm jumps right to where it would be had I not added that key!

Is this an incorrect way to correct an fk animation or something?

How can I get my FK arm to go the right way, or do I have to use IK?

Tia for any help

Have you tried editing the IPOs for the bones?