Why is my Model's leg twisting when rigging?

Alright so I’m using rigify to do my rigging. Its cool, it worked nice. But when I went into rigging my Lions arm upward it just starts to twist my mesh at the elbow point. It looks all weird and nasty.

I noticed the bones begin twisting as I do so.
Am I reaching a limit like is it acting this way because a bone cant realistically do this, or something like that?

If ay one can tell me why this is happening I’d really appreciate. :slight_smile: