Neurologists call it the "commonest movement disorder you've never heard of". Restless Legs Syndrome (RLS) – or Ekbom's disease – is the uncontrollable urge to move your legs when resting. About 5-10% of adults will develop it (around five million people in the UK), but while some will just experience a sporadic twitchiness at the end of the day, for others the condition is a torment.