Sitting with your torso flexed 135 degrees from your legs — halfway between bolt upright and flat on your back — is best for your spine, even though you’ll have a tendency to slide off your chair, say a team led by Waseem Bashir of the University of Alberta Hospital in Canada.

On the basis of MRIs, the researchers say the 135-degree position is better than sitting upright or leaning forward. 32% of people in the UK spend more than 10 hours seated, and half don’t leave their desks even to have lunch.