One elbow moves the wrong way.

I’m trying to make a rig for the astronaut from the game “Space Engineers”. If I move down the hand on one arm, the elbow bends down as if he is waving, which is good. On the other arm when i move the hand, the elbow goes up. I DID DO ONE ARM THEN DUPLICATE IT TO THE OTHER SIDE*. Did I screw up somewhere or forget to change a setting? Thanks.