In case there was any doubt that back pain from sitting at an office desk is a huge problem, consider these statistics: in the UK alone, 2.5m people have back pain every day. Back pain costs the country ￡12.3bn ($20bn) a year, according to Cardiff University. In a recent EU survey, 36 per cent of European workers reported having back pain, the number one problem cited.

Obviously, some of these back problems are caused by manual labour and others by pre-existing conditions such as disc ruptures. But sitting down all day is probably the primary cause of back pain, and most people do not even make the connection. You can usually tell who these poor people are because they walk around the office tilted forward from the waist like a human leaning tower of Pisa.

One solution is to use a standing desk for part of the day, as I suggested in an earlier column. But some workers do not have that option; and for executives who travel a lot, sitting on an aeroplane has become a weary fact of business life. You can get back pain even in the cushiest business-class seat.