#cruxification

Square wrought iron nails were driven through each  wrist (not the palm of the hand like many people assume) and deep into the wood. The feet were then extended and a larger nail was driven through the arch of both feet, one placed on top of the other. 

There was some flex in his arms that allowed Him to sag, which would pull on the nails in His wrists. This kind of sagging would make it possible for Him to inhale, but impossible to exhale. In order to do that, He would have to push up on the nail in His feet to get that breath. That's placing all His weight (lets say around 150 lbs the average male weight) on a single nail in His feet, crushing the bones and nerves in His feet. 

The cycle of pushing up and sliding back down would rub His already damaged beyond belief back on the rough wood of the cross. The muscles in His arms and chest would also begin to cramp. Eventually one no longer have the strength to lift up and they would suffocate. This could take days.   

But as this is happening, Jesus' the chest fills with a clear serum which compresses the heart, causing even more pain. His heart would struggle to pump blood through the tissues, and His lungs would be struggling as well. 

As Jesus can feel death is near, He pushes Himself up and gives His last cry, "Father, into your hands I commit my spirit."