Rigging with Rigify: Problems with mesh

Hi everybody!
It’s me, again, with a new problem.

I make the rig with Rigify and when i go to edit weight paint, doesn’t matter what i do, when i move the IK hand or foot the behavior of the mesh are very stranger.
See the gif:
https://media.giphy.com/media/3o8dFgU0OH4oUhI29q/giphy.gif

What i can do?!

Thanks good people!

Weight paint it better.

Try tutorials: Part 2 for basic mesh preparation, Part 4 for skinning basics, Part 7a-7g for a complete rigging/weighting workflow.

Good luck!