A young reader asks a questions about backpain from sitting:
About two weeks ago I noticed some lower back pain when standing up from sitting. Yesterday and today it hurts so bad to get up that I clench my teeth when I stand. It's so low that it's about where I'd think my tailbone is. It's not a large area that hurts its right in the middle(also why I think it might be my tailbone). I haven't fallen or been exercising excessively. It's about two inches down from the top of my butt. I am only 18 and relatively healthy.
When you sit the pressure goes straight from the chair into your spine. Your butt muscles aren’t much help in distributing the spinal load while seated. Also, butt muscles house the sciatic nerves, and these are pinched by the weight of sitting.
A 20 degree slouch in sitting makes spinal pressure go up 185% when compared to standing."