Roman crucifixion was a long, drawn-out process that often lasted for several days. This was not the case for Jesus - "Pilate marveled that He was already dead…" Mark 15:44.
What happens on that cross?
• With weight on the wrists - the chest is stretched when the person is slumped over - able to take only shallow breaths without a full exhale - pain increases on the wrists
• Weight is transferred to the feet and the person pushed up- full exhale is possible - pain increases in the feet
• Time after time the person slumps down again - eventually exhaustion makes the transfer of weight to the feet impossible – the person can’t push up anymore and the respiratory muscles cramp and stop working – this process is sped up when the lower leg bones are broken
• There is also a slow buildup of fluid (serum) in the lungs and around the heart
We see the evidence of these effects when a Roman soldier uses his spear on Jesus - John 19:33-34 "33 But when they came to Jesus and saw that He was already dead, they did not break His legs. 34 But one of the soldiers pierced His side with a spear, and immediately blood and water came out."