For warriors or laborers, I can imagine breaks were fairly common — as they are today. What kind of understanding of the body did they have in practical situations? Did they heal effectively and return to their normal lives?
Breaky breaky, what do?
This has been answered before: https://www.reddit.com/r/AskHistorians/comments/2b8j0d/before_modern_surgery_how_did_humans_fix_their/
But in short, strapping the limb in place and bed rest.