[dr_zoidberg]

I sometimes do a gesture similar to this one as a habit for cracking my (thumb) knuckles single-handed. Not as an intentional sign first tucking the thumb in the palm, and then traping it in, but rather as a single motion. I wonder if it could be mistaken for this gesture.

[corobo]

No. Rapidly moving your fingers to crack your knuckles is not the referenced hand gesture

[dr_zoidberg]

I don't do it rapdily, and it's a single-handed motion, so not the usual "cracking your knuckles" movement/gesture. I do wonder because it could look similar, though I don't specifically direct it so that it'll be palm-to-viewer, as the guides for this gesture tell you to do.