Programmer’s hands

This is my back view. You can see my palms facing backward. I realized it as my wife and kid largh watching me walking. They say “You swing your hands like swimming!”

My hands used to be attached to my body in the normal way when I was a kid. Why it is like this now?

I guess programming 6 to 10 hours everyday for 26 years has changed the elbow joints. I’ve been typing keyboards everyday ever since I entered the university.

Probably I’m not the only one among programmers. Do you know anybody who owns “programmers hands”?

-Fujita