Simply remove the head bob so you wont feel like a freakin Bobblehead when running for your life in the zone.
For those who don't want to bother extracting all of the game files just to remove the head bob. It's a lazy fix I know but I don't want to tweak with the files everytimes I re-install the game.
Copy the archive in your game directory
The changes made to the effector.ltx :
run_amplitude = 0.0
walk_amplitude = 0.0
limp_amplitude = 0.0