As far as how ancient crucifixions were performed, it's important to remember that there was a wide range of activities translated as 'crucify.'
Sometimes this was merely impaling people on poles, a la vlad tsepecs.
Sometimes it was done in the highly stylized form seen in most catholic iconography (they did it with professional crucifixion teams when they
Spartacus revolt was put down. They lined the Appian Way, a 90-mile highway, with the crosses of dying slaves . . .)
sometimes they'd nail a person's hands and feet to a tree. (typically for violating a sacred grove, or desecrating temples, etc.) They might use
ropes to hold the victim in place, so he didn't "rip free."
The Greek word Chieros means the arm from the elbow to the fingertips. So piercing the hands cold also include the wrists, or not.
We have intact ankle-bones from crucifixion victims, with the nails still wedged between them; but the hand and wrist bones don't articulate in such
a specific fashion. A nail generally just forces the bones apart.
But most archaeologists assume in a general way that Jesus was probably pierced between the radius and ulna of the forearm. Again, there's no
specific record in the gospel accounts.
* * * * * * * * *
Stigmata is a separate question, of course.
I suppose that if a person can upset themselves so much that they have a heart-attack, then I can accept the idea that they could also have a
detrimental affect on their own anatomy.
I've read a number of articles on stigmata; generally it is associated with specifically meditating on Christ's wounds and his suffering, prayed
about over a period of months. The movie of the name "Stigmata" was so atrocious because the victim doesn't welcome the suffering, whereas most
I think a person really could make themselves sick by focusing on it.
St. Francis of Asisi is the first stigmatic on record, in the late middle ages. His case was totally unique in that the flesh itself began to take on
the shape of nails imbedded through his hands and feet.
Yeah. look it up. Here's one quote:
When the vision disappeared, St. Francis felt sharp pains in various places on his body. Looking to find the source, he saw that he had five marks
like those on Jesus' hands, feet, and sides. Observers described them as "fleshy" and "nail-like ... "round and black, standing clear of his
flesh." His side appeared to have been lanced; his companions actually saw that wound appear, as though his skin had been slashed. During the days
that followed, St. Francis' trousers and tunic were often soaked in blood. The marks remained until his death and reportedly caused him much pain.
That came from this site: www.workersforjesus.com...
This one is about Francis generally: www.cin.org...
Here's a list of famous stigmatics:
And finally, a pretty good article from "The Skeptical Inquirer" with a discussion of fraud issues: