Interesting topic.
I believe that there is a fair amount of research that has been done on athletes, dancers, etc., who have similar strength, coordination, and "muscular memory" issues as do instrumentalists; looking into the effects of visualization on neural pathways and improving performance.
Here's a sample article. Too bad about the background, which makes the article nearly illegible. If you copy and paste the text onto a white background one can read it better...
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Apparently, when we think, in a very vivid, engrossed way, about doing a motion, or series of motions, our brain triggers the muscle movements/impulses as if we are really doing them.
When I can't practice on the bass, I run through things in my mind, as if I am playing, either with the music or by memory. I find that it actually seems to improve my playing, because I don't get hung up the instrument's resistance or hung up in my own technical shortcomings, etc.
Visualization is powerful stuff...
In addition to that, I took one of those funny bass ukeleles on a trip, recently, just for practicing. When I came back to the DB some stuff I had been working on had gotten better, surpringly...