JOEL - The Romans knew that very well. When crucified persons were nailed rather than bound with ropes to the cross, the nails ordinarily were driven through the feet and wrists so that the weight of the body could be sustained. Nails were rarely driven through the palms. Isaiah's prophesy of Christ tells us, "And I will fasten him as a nail in a sure place;"(Isa 22:23) the "sure place" being in the wrist part of the hand.
Roman historical accounts and experimental work have shown that the nails were probably driven between the small bones of the wrists. Nails driven trough the palms would strip out between the fingers from the weight of a human body. Some believe the misconception of the nails being in the palms may have come about through a misunderstanding of Thomas' words, "Except I shall see in his hands the print of the nails" (John 20:25, Also 3 Nephi 11:15).
Anatomists, both modern and ancient, have always considered the wrist as part of the hand. (Davis, C.T. "The Crucifixion of Jesus :The Passion of Christ from a Medical Point of View". Ariz Med 22:183-187, 1965).
However, it is known that there are more nerve endings in ones fingers and hands than any other place on the body which makes them very sensitive to pain and pressure. Therefore it is possible that in order to cause the most suffering and pain, nails may have also been driven into the palms of Jesus.
Other studies have shown that the cross the Romans used may have had a protrusion about half way up which served as a seat for the victim to sit on(Against Heresies 2.23.4.). It is also believed that there may have been a small platform under the feet to help support the body. This would mean that nails in the palms and/or wrists would not have had to carry the entire weight of the body.