The idea of “stages of RSI” arose in Australia in the early 1980’s, when people were trying to become more “scientific” about the problem. The idea was that early stages were supposed to be easy to cure, but late stages were “incurable”. However many people diagnosed with “late stage” got better, and some with “early stage” did not, so the concept turned out to be fairly useless as a predictor of outcomes.
Also, the same person might have some symptoms from early stages and some from late stages all at the same time, so the reliability of diagnosis was low. The final problem was that it gave people an impression that the problem “progressed”, which in most cases was not correct, but raised a great deal of alarm in the person with the problem.
Comment I agree with your whole message and particularly the ‘diagnosis with late stage’ bit – I had symptoms which were, according to one book, characteristic of the ‘last stage’ of RSI, and therefore basically ‘incurable’. This was an enormous downer – only when I learn more about RSI and tried a variety of treatments did I realize the stages idea was rubbish, and went on to make a near-complete recovery.
My advice in general is: If anyone tells you can’t recover from RSI, ignore them – only believe this if you have tried a wide variety of treatments suggested by experienced (in RSI) practitioners and by people with RSI.