As @turnitaround has already posted. Use It or lose it. I wouldn’t claim to offer an explanation but a few clues might just be …
Exercise, Deconditioning etc
The advice is, repeatedly, to walk as much as possible
Oh and I’ve a husband who does one hour exercises daily without fail for an arthritic hip joint which keep his symptoms totally under control so he can be on his feet walking and gardening all day if necessary. Three weeks off due to a hernia op and he was barely able to walk across the room. Not sure how much of that could be credited to neuroplasticity though. Very little I suspect.