So when using stat.walkOneCm it'll causes the score to fluctuate and trigger once more with a slight delay after the initial movement has ended.

Commands:
/scoreboard objectives add test stat.walkOneCm

On a clock:
/say 1
Meant to "clean up" the chat so that it's easier to see when the score updates or not.
/scoreboard players set @a[score_test_min=1] test 0
Resets score.
/say @a[score_test_min=1]
Tries to find player that has walked.

How to reproduce:

Method 1. Simply walk and then stop, if done correctly, chat will spam your name while you're moving. Then when you stop moving, chat is spammed by '1'. Maybe a second or so later, your name will be displayed once or twice again, concluding that the score is infact applied once again after short delay.

Method 2. Jump or sprintjump, whilst moving slightly (only when you're in the air). When you land your score will be modifed and the same thing as with #1 will happen. It does not matter how far you move in the air, as long as you've moved in the air it'll consider that you've moved or something when you get back down again.