Originally posted by Displacer
I tend to lean over my chair and relax for a while sometimes, but i put A LOT of pressure on the back of my elbow onto the head of the chair...

I guess that's your problem , cuz it's very unlikely to get strain in your fretting hand elbow from playing guitar ... You know , some people get pain in their back due to wrong sitting position .
You should push yourself to stop bad sitting/standing/etc habbits , cuz they can lead to serious injuries and problems as you get older.