If one of the snow-buried sidewalk tiles is raised higher than the others; don't push a snow shovel with your hands against your chest, when you pickup speed and then slam to a stop on the raised bit...

I haven’t shoveled snow in years but you just brought back some surprisingly good memories of shoveling snow in my teens.

I had a similar experience walking over a set of bars (on a hog feeder, not a playground), slipping, and landing right on my diaphragm on top of a bar. It was a small eternity before I could take a breath.

I also did that and had never heard of getting the wind knocked out of you. I thought I had collapsed my lungs and was going to die. I tried to tell a friend but couldn’t talk obviously. So I just sat on a bench to accept my fate. “Mom will be very sad” I remember thinking.

Fortunately the breath eventually comes back…

That is very interesting. I had a similar experience when I was I child. I had a toy electronics set and thought of using an outlet instead of the weak battery. Of course I got a nasty shock. I was sure I would die know. I wasn't really scared or upset about that. More about how my parents would feel. It wouldn't be fair that my father had to carry his dead son out of the house so I sat outside against the wall of the house waiting to die. Reading your report makes me wonder if this is just the state of mind of a child.

+1 although it was a climbing tree in my case from which I wanted to abseil (with a very thin rope)

I fell from one of those long balancing logs straight onto my back.

Icy playground. I managed to skid, trip, fly, and then land on the upturned hard-shoe of another kid. He ran off laughing oblivious, I could stand but was unable to breathe properly for a few breaths

When I was 6 or so I did the same off a rope swing hanging from a tree. I guess I was lucky because another kid broke their arm off the same swing not too long afterwards.