"Laid back" position said to be best

The BBC is out with a report this morning that persons who sit at their desks for prolonged periods should NOT sit upright (as I believe all of us were told in school and by parents). The best posture is leaning back at an angle of 135%:

In this study, the patients assumed three different sitting positions: a slouching position, in which the body is hunched forward as if they were leaning over a desk or a video game console, an upright 90-degree sitting position; and a "relaxed" position where they leaned back at 135 degrees while their feet remained on the floor. The researchers then took measurements of spinal angles and spinal disk height and movement across the different positions.

Spinal disk movement occurs when weight-bearing strain is placed on the spine, causing the disk to move out of place. Disk movement was found to be most pronounced with a 90-degree upright sitting posture. It was least pronounced with the 135-degree posture, suggesting less strain is placed on the spinal disks and associated muscles and tendons in a more relaxed sitting position.

When they looked at all test results, the researchers said the 135-degree position was the best for backs, and say this is how people should sit.

More information at this BBC link. The source of funding for the medical study is not reported; one wonders if the makers of wireless keyboards had a hand in it....