RSI is a frustrating stuff as it is not easily diagnosed, treated, nor is it fully debilitating.
Many sufferers are able function normally with minor deleterious effects.
Causation is not predictable either. The problems tend to concentrate in the wrists and hands but can extend up to the elbows, shoulders, neck, and even the jaw. As a flutist, I have explored the possibility of TMJ, a disorder stemming from the temporomadibular joint, or more succinctly, the jaw, as a possible causational variable. It is stipulated that TMJ can cause a host of neuro-muscular symptoms not unlike those caused by the standard ilk of RSI related maladies. However, the camps are rarely in concordance with regards to the treatment.