"Saint Bridget of Sweden could not have been more specific about it: "they transfixed His hand in the part where the bone was firmest." (Revelations to St. Bridget, TAN Books and Publishers, p. 45)."
Brother is correct that a nail through the Z space would come out at the base of the hand & thus would coincide with the shroud of turin which appears to show blood in this "wrist" area.
Hanging from a cross beam, gravity would have caused the blood
to pool at the bottom of the back of the hand, which is close to the wrist and perhaps gravity caused some blood to drip & coagulate onto the wrist area. Still, the wound area would have been in the z part of Jesus' hand.
The "bright" spot that shows up near the wrist area on the Shroud of Turin is "blood." Indeed, the Shroud if full of blood stains as scientists investigating the Shroud reported.
Note: When Jesus appeared to Thomas he told Thomas to put his fingers into his "hands".