Yes, you can break your finger by punching somebody in the head. My brother broke his thumb when he smacked his friend in the head with his hand!
Hi
It is possible for one to get his finger fractured by mild trauma such as punching. It all depends on the force of the impact.
Any increasing pain (localized), numbness, or tingling in the fingers needs urgent evaluation by a doctor. The diagnosis would depend on X-ray or CT findings.
The Boxer’s fractures are treated by immobilizing the joint using a variety of splints, a cast, or taping techniques. “Buddy-taping” involves taping the little finger to the ring finger. It typically takes four to six weeks for the fracture to heal and thereafter some more time to regain motion and strength.
Take care and do keep us posted.