"Furniture for everyday sitting is a relatively modern, European invention. When not standing, primitive peoples sat, squatted, or lay on the floor. Many Asian nations, including the Japanese, still prefer to do so."

"Individual chairs ... did not join the standard household inventory until the sixteenth century... They were not widely used in schools, offices and workplaces until the end of the nineteenth.
Unfortunately, flat-bottomed chairs do not match the requirements of the human anatomy. Unlike the horse-saddle, which transfers much of the rider's body-weight onto the stirrup, leaving the natural curvature of the spine intact, chairs lift the thighs at right-angles to the trunk and disrupt the equilibrium of the skeleton. In so doing, they put abnormal stress on the immobilized pelvis, hip-joints, and lumbar regions. Chronic backache is one of the many self-inflicted scars of modern progress."

From EUROPE, A HISTORY by NORMAN DAVIES. Oxford university Press, 1996.