soccerdude84 :
I don't know why every gaming chair has to have dumb flaps on either side of the seat and backrest, all they do is limit your freedom of movement. Unless you're actually playing a racing sim you're better off with an ergonomic chair.
These are called side bolsters, and they're what Th3pwn3r was talking about. I totally agree about the ergo chair. Aside from affecting fit, the bolsters also limit air circulation and make the chair hotter.
To me, they're utterly pointless, unless your racing seat has actuators that physically toss you around. The reason sports cars have them is that when you're pulling up to 1 G of lateral acceleration, they help keep you from sliding around. A proper racing harness does a better job, however. Either one makes the car more controllable, because you can't steer as well when you're also having to use the steering wheel to hold yourself in place.
BTW, I lol at anyone using a racing harness in a street car. They're damn inconvenient, in day-to-day use. And without an anti-submarining loop, 4-point harnesses are more dangerous than the factory 3-point belts.