When I did this, I had a perfect storm of conditions that made the drop much worse. I thought it was a ramp so I did not expect the drop. It was a tall curb from a sloped sidewalk. I was carrying a large garbage bag so my back was arched and my head was back so there was no normal S curve in the spine to absorb any of the impact. I jarred my pelvis, back and neck and messed up my shoulder. It required physical therapy for my pelvis, back and shoulder. I also knew I had rung my bell with this event.

Since then, I did an unexpected step off a front porch but without my back arched and noticed the jolt but did not suffer any symptoms at all.