Back when I was a younger bull we had a 20 year old kid with MD in the youth group at church. One outing was a 2 mile hike to the top of a mountain, maybe 1000’ elevation change.
He couldn’t make it so I carried him on my back. On the way back down it was easier for me to go fast bouncing from point to point on the trail.
About 1/2 way down he screams out STOP! “What the matter, are you hurt?”, I asked. ‘No, but you’re beating the heck out of me’.
He walked the rest of the way down.
Once I carried an eleven-year-old on my shoulders as a group of us walked a mile down to the beach—thought nothing of it. Fifty years later my neck still locks up on me chronically.