Hey you guys, don't forget that many hospitals aren't as forward and up to date on birthing techniques and preferences as many of you are.
Not defending or taking sides just offering a differing POV.
They aren't doing it specifically to be barbaric. They are just stuck in their old ways. Those arm boards are pretty narrow and there is lots of pulling and pushing during the delivery. They just don't want to lose any venous access they may have if something did go wrong. They also don't want your arm to fall off and cause any injury to you.