@amolith Bracing your thumb against the second knuckle of the index finger, instead of wrapped under the fist like "normal", actually reinforces your wrist and makes it less likely that you'll break *that*. It's a valid hand strike in many South East Asian martial arts. The thumb has to be braced, though.

Not that the model is doing it right. She just has her thumb flat against her hand with her silly long nail sticking out asking to be broken . . .