Can you rotate bones within an IK Chain and allow the IK Target bone to move along with it? I have a robot arm rigged with an IK and down the chain of the IK there is a joint specifically for rotating on the bone's Y Axis that allows the entire lower arm to rotate. However once I move the arm into position with the target bone and then try to manually adjust that joints rotation it locks up because the target bone is stuck in place and won't adjust itself automatically. I know this is normal but is there a way to allow the target bone to move freely if another bone is pulling against it?

For those curious or if it helps at all I am trying to make the robot wave but the only way I can get that to happen is if the lower arm rotates. And I don't mean with a pole target either. Imagine bending your elbow to 90 degrees and rotating your hand. 

Thank you!
I came up with another solution. I reduced the chain on the IK by a couple and then added IK to the top part of the robot's arm just above the rotator joint. Then I made the IK chain go the rest the way up the arm to the shoulder joint. now I have 2 controllers one that controls the shoulder and top arm location and then the bottom arm can move freely with its own controller bone.