Wrist. And feet. yea to be pedantic but brevity is the soul of wit.
There are scholars in religion/anatomy that suggest the nails would have to go through the wrist or just above to hold a body in place. It is a plausable theory. Like the story? But I submit there would have been rope initially as any carpenter (sic) will tell you about nailing up a ladder. And maybe there were second nails just to be sure (whichever came first).
Nails were an unique exception, Roman crucifixions normally used rope - ask any Spartacus!