A semantic analysis showed that the original language used a noun that considered the hand and the wrist as one. In fact, I know a person from a third-world country who uses “hand” to mean all the way up to the shoulder, although if you pin her down she will acknowledge the modern hand ends somewhere short of that.
Nevertheless, it has been shown in modern research that the two palms can support the weight of the entire body (I think it was a National Geographic special of some kind), and if ropes are tied at the wrist in addition there is really no question at all. So I don’t think the precise anatomical location of the stigmata can be taken to disprove the miracle (especially when it already has been approved by the Church).
I'm not Catholic, so I am looking at the issue almost like a forensic detective. In 1917 anybody wanting to make fake stigmata would have thought of the palm of the hand. That is one of the reasons I believe the Shroud is authentic, it does not match the preconceived ideas of Renaissance Italy.