You don't have to flatten them out to pass half guard...try the easy way instead...
The most in depth Kesa Gatame Crush
Easy Ways to Kill the Arm in Side Control and Scarf Hold Tricks
How to Save your Knees While Training BJJ and Q&A
Invisible Jiu Jitsu Live Q&A
Adam Wardzinski Shows His Favourite Sweep
I Was Wrestling Wrong for 15 years! ~~~ Re-evaluating the Shot in Jiu Jitsu
The One Easy Key to a Great Triangle Choke
The Arm in Guillotine
Aleksei Oleinik Armbar Breakdown!
Attacking the Half Guard with Guillotines - Submissions and Passes
Using Knee Strikes to Set Up the Clinch.
A Filthy Wristlock For Filthy People
Best Mount Escape via Deep Half Guard