Anyone who has endured a long-haul flight wedged into a cramped middle seat knows that a few extra inches can make the difference between arriving refreshed and stepping off the aircraft with stiff knees and an aching back. While premium cabins often steal the spotlight with lie-flat beds and private suites, economy is where most travellers spend their journeys. And increasingly, airlines are recognising that comfort at the back of the plane matters just as much.

