What type of martial arts does Tony Jaa use in the bone breaking scene in ong bak 3?

Tony learned stunt-work first (actually at forst he copied what he saw Bruce Lee Jackie Chan and Jet Li do first), sport Taekwondo second and Muay Thai third, so in his films he uses a blend of all three of those. It creates a really cool action scene I think you'll agree, but sometimes it does strain credulity. Also, if fifty guys came after one person, even if that one person is the lovechild of Bruce Lee and Mike Tyson (Tyson Lee would be his name and he'd smash your children until they were like water) The fifty guys would win.