Leon Morris describes a few of the details of Roman crucifixion
by Mr. Sheehy
Very simply Luke tells of the crucifixion of Jesus, the supreme sacrifice for the salvation of sinners. In this form of execution a person was fastened by ropes or nails to a cross (which might be shaped like our conventional cross or like a T, an X, a Y, or even an I). Jesus’ hands were nailed (Jn. 20:25), and probably his feet also (cf. 24:39), though none of the Evangelists says so in set terms. There was a horn-like projection which the crucified straddled, which took most of the weight and stopped the flesh from tearing from the nails. The discovery of the bones of a man crucified at about the same time as Jesus raises the possibility that the legs may have been bent and twisted, then fastened to the cross by a single nail through the heels. Such a contortion of the body would have added to the agony. Crucifixion was a slow and painful death, but it is noteworthy that none of the Evangelists dwells on the torment Jesus endured. The New Testament concentrates on the significance of Jesus’ death, not on harrowing our feelings.
Morris, Leon. Tyndale New Testament Commentaries: Luke. Grand Rapids: Eerdmans, 1999. Print.