Conor McGregor's early hammer fist punch draws warning from referee - SBNation.com
Hammer Fist Boxing Club
What & when is the proper use of a 'hammer fist' in MMA and how does it compare to a typical knuckle punch? It seems like it would be less effective. -
Hammerfist : Krav Maga Technique: How to Fight w/ Hammerfist to the side : Self Defense - YouTube
Hammer Fist Multi-Use Striking Tool - Pro Tool Reviews