David Leisner is an American classical guitarist. During the 1980’s his performing career was cut short due to focal dystonia. After 12 years Leisner rehabilitated himself and has resumed an active career. Leisner was one of the first performers on the world stage to 'beat' focal dystonia. There are lots of places online you can read about his story.
Using what he calls 'the big muscles' in the shoulder and back, Leisner developed a new technique of playing the guitar that bypassed the muscles affected with FD
See how focal dystonia affects different musicians