In general support of the earlier post by Mike Bird, I offer this piece of evidence. Although not directly related to the act of crucifixion, it is widely known that the Romans portrayed their conquered in feminine ways.
Consider the picture here. It depicts a conquered people under the hand of a victorious Roman emperor. The sculpture clearly presents the conquered as a female. I took this photo in Aphrodisias (which is in Turkey) this past year.
So to the extent that Jesus was a conquered person, Rome would have feminized him. And it makes sense that the crucifixion underscored this element.