spinning topology question

Hey guys, I’ve been wondering this for a while now, but why are many character artists using one long spiraling edgeloop for arms or legs instead of using many loops? Is there an advantage ?

You need to show which spiral edge loop you are talking about.

Most muscle runs diagonally around our body. And that if you create an edge loop around the muscle form, you can define that shape better in 3D. Here is the image of arm muscle form. Noting is straight is it?