Muscular dystrophy … was never seen until Duchenne described it in the 1850s. By 1860, after his original description, many hundreds of cases had been recognised and described, so much so that Charcot said: ‘How is it that a disease so common, so widespread, and so recognisable at a glance – a disease which has doubtless always existed – how is it that it is recognised only now? Why did we need M. Duchenne to open our eyes?’