My friends and I used to do this as kids. If you lean sideways-on to a wall, purposely putting pressure on the arm between your body and the wall for a minute or two, and then step away, your arm starts to rise up.
Really: try it.
Why does this happen? It feels like your arm suddenly becomes light - is this just because of the release of pressure on it? Why is it such a struggle to actually stop the arm from rising? What’s happening physiologically?
[hijack]
When I was a kid, we used to do this. But we stood in doorways and pushed both arms against the doorframe. It’s cool to have both arms rise into the air.[/hijack]
You’ve asked all those mitochondria to get into action and create eneergy… lift the arm…more and more get involved…they flurry into action, creating the forces and converting energy to lift the arm…they keep converting energy to make the muscle move…the muscle is flexed for that degree and angle of release…
…you step away and the energy is released.
That makes sense. Thank you **Philster[/].