From the man a rib was removed. She can clearly manage on her own. of course, every rib wants to be reconnected with her match some day, hopefully.
the man's muscles are so he could remove difficulty from his rib, and not cause it harm. But ready to make nothing of every beast that may try to hurt his rib.
some beasts have two legs. Why do you harm your rib, I asked; she's not exactly my rib, he answered. I wonder, why are you with her then? is it so you could damage her that she will'nt fit when she finds her match?