L.B.
As my son began breaking free of the swaddling blanket, I started using a larger (thin) blanket that we could wrap around him more tightly. This helped for a few weeks. After that, I found that he still wanted to be swaddled, even if we only did it below the arms (I know that doesn't help with the arms waving around part, but it was soothing to my son to still be somewhat swaddled). Good luck!