Well, competitive gaming is always dsmaging due to repetitive movement... That also works with chess, since physical shape helps oxygenation and mental performance, chess players need to have physical stamina...

But I'm talking more about casual play. (But you are right, computer gaming can cause early arthrites and so on..)

I guess you are saying physical sports... So, not counting E-sports or Chess...

I have seen skeletons... Cranium skeletons in universities... In that way they are really look alike. I can see how people would mess it up, speacially because skeletons are usually named the collection of our bones, but there are always teeth (and some cartilage on the rib area)

Yeah, I have fallen through the same trap before...

They really look like though

I mean, I guess it is reminessence of the thermometers.

Hot things expand, so it will go up.

If you put a thermometers upside down, I can't recall if geavity interfeers, but I guess. If you look at boiling water on a pan, the water rises...

I think those are a few of the reasons why the direction is upwards. Not totally arbitrary. But I don't know

We have many other charactheristics, like sweating that we take for granted