I watched the world record speedrun and saw shadow moving in low gravity? Can anyone explain to me how this can be performed?

The tube that Shadow is standing on is interesting. Normally if you get inside of it, the gravity will change in order for you to move all around it (example : you can run on the ceiling and stuff). The spring at the end of that section will disable it and make your gravity shift back to the way it was before you entered the tube. Now, the trigger that makes the gravity change happens to extend outside of the tube, specifically in a little spot. Just far enough so Shadow can be outside of it and still activate it. And since he doesn't interact with the spring... Hopefully that answers your question.