Performers often have the impetus to grab the instrument from someone they are listening to, saying, "No! Do it like this!" Of course, we don't usually do it, but we pretty much always think it. So, when I attended a piano trio concert last night in which the trio was playing repertory that I used to perform and know, I was experiencing physical memories as I watched and listened. To make it more intense, the cellist was not bowing well. He was forcing in order to try to get big sound. Big sound is drawn from the string by encouraging vibrations to become huge. Instead he was squashing the strings, especially in climaxes. (He broke many bow hairs--a sure sign of forceful pressure.) Thus, not only was I reliving passages that I once knew so well, but I was also involuntarily sending mental vibes to the man on how he should be bowing in comparison to how he was bowing.
Today my right (bow) arm is downright limp. It hurts to use it and it won't lift very well--not because of muscular pain, but because nerve impulse conduction is somehow all screwed up. I guess my neural pathways became overloaded simply due to my imagination, which in this case is probably almost as solid and realistic as actually bowing, due to 30 years of practice.
What a corner to be backed into: having a highly trained skill that overloads the neurology upon use. Can you believe that simply imagining is enough to overload my right arm!?