It has become popular in movies and books to have heroes carrying their weapons on there backs for over the shoulder drawing. But, with just a little experimentation, this seamed a little impractical. Walking and moving was usually easier, but drawing was an annoying, time-consuming process that required the use of both hands, as if climbing/pulling a rope hand over hand. Was this sort of carry even historically used, and if so did they have some special method for easy drawing? This picture http://images.cloud.worthpoint.com/wpimages/i...10e7d9.jpg shows one contraption that looks like it would work, but I'm not convinced it was ever used historically. Could anybody shed light on this issue?

There is a long and entertaining thread on this very subject located here:

Wearing a sword on one's back

If you owned a longsword, you also probably owned among other things a horse. You would not need to carry anything on your back. But even if you were horseless, and travelled armed with a longsword I think reaching for your back would be a bad idea if you were attacked. The longsword is ...long and you would have to pull it way above your head and probably bend down (to a perfect decapitation position) before you can swing it. That means you are very exposed.
If you are carrying your sword the normal way, hip-hung in a belt, you can defend yourself while the sword is still in the scabbard. You can hit with the pommel, block cuts with the scabbard and use your arms, all while the sword is on it's way out of the scabbard.