Dosch, Rocketbox and AXYZ all use this position, so there's got to be something to it.

http://www.doschdesign.com/products/3d/3D_People_T-Pose.html

https://secure.axyz-design.com/

http://www.rocketbox-libraries.com/index.php/characters.html

I'd rather stay in my lane than lay in my stain!