Comment Re:Cite please (Score 4, Informative) 228
http://www.thefreelibrary.com/Repetitive+strain+injuries+stretch+higher-a018341055
when you work through the reports, the 300k number works out to about 100k for IT. while this report is old, nothing has changed to drop the rate. uk reports are more current
http://download.microsoft.com/documents/uk/hardwar/Ergonomics_and_Repetitive_Strain_Injury.pdf
As for the near 100%, think arthritis, medication induced tremors, loss of flexibility as you age normally or via trauma. It all adds up to loss of hand function.