“Running in place”, meaning to exercise by doing the motion of running when one might (for some reason…) be unable to go anywhere.
One proposal I’ve heard is kuri surloke. But surloke has been used to mean “on-location”, as in catering or cinematography; if it seems clear in context, I’m okay with that, but I’m not sure it is clear.
Kuri senmove seems like nonsense, as is kuri with various adverbial forms of halt- (halte, haltade, haltante, etc.).
Kuri nenien means something else, but it made me wonder: kuri senmove would mean “run without moving (making any motion)”, which is nonsensical, but perhaps, “kuri senmoven” might be acceptable? Or kuri senloken?
Reading a physics text I got the sense that Esperanto doesn’t have good words for “motion” meaning a change of position as distinct from “motion” meaning, for instance, waving one’s hands around—that sort of motion is usually expressed via talking about traveling or using verbs of motion.