You boy! Over there! Slump down and pay attention. For generations, we have been told that an upright posture brings productivity and a life free from back pain. The word "slouch" is redolent of laziness and moral decrepitude, which is why it is surprising I can even write this, slumped at a deckchair-style 135 degrees.
Far from indicating that I am a decadent cad fully deserving of spinal agonies, this rakish angle is, according to researchers, the ideal posture for office workers. If you sit with back and legs at 90 degrees, nearly all upper-body weight is concentrated on the lowest two spinal levels. Spinal disc material can shift out of line, leading to chronic back pain, according to the study of 22 volunteers at Woodend Hospital in Aberdeen.
Source - Guardian