Sometimes I tell my violin students to think of their fingers as "little legs" and we do leg movements first before trying a technique on the violin. Several weeks ago I was at an empty tango practica, practicing boleos, and I realized what I needed to do to clean up my boleos is to contract my hamstring at a certain point. It's easier with the right leg, since my left hamstring was one of the later muscles to come back to life.
Anyway, a few days ago I was practicing trills on the violin, something that's still tough and kind of hit-or-miss since MS, and I realized that the motion I need to perfect for trills is the same kind of motion I need to perfect for boleos, just with finger muscles instead of leg muscles. This is weird and cool and cosmic all at once.