The headless woman pictured at left is working really hard at sitting with good posture but it turns out sitting up straight is pretty stressful on your back. According to LiveScience, sitting back at a 135 degree angle is better than sitting up at 90 degrees or leaning forward.

Using a new form of magnetic resonance imaging (MRI), researchers studied 22 volunteers with no back pain history. The subjects assumed three different positions: slouching; sitting up straight at 90 degrees; and sitting back with a 135-degree posture—all while their spines were scanned.  "A 135-degree body-thigh sitting posture was demonstrated to be the best biomechanical sitting position, as opposed to a 90-degree posture, which most people consider normal," said study author, Waseem Amir Bashir, a researcher at the University of Alberta Hospital in Canada. "

I'm finding it really hard writing this entry in the correct position. I need longer arms.