An Odd Question About Chinese Swords

If I had to hazard a guess as to why they do it in the movies is because the sheath would make a decent parrying weapon if needed.

The hooks presented here are indeed antique, this version represents one of three common variations I have encountered so far. These include:

1. Hooks with a hinge that attach to a section with two half rings on either side, or a large ring that has a bar in the middle. (Current example. Used on Imperial sabers of the 18th century and appear to be found on more common sabers dating from the 19th century.)

2. Hooks with a decorated "shield" under which there is a hinge that holds a ring. Common 19th century type for flashy swords that were made to look like 18th cent. examples. May have a precedent in the 18th century, but I haven't seen them yet.

3. Hooks without a hinge, made from one piece entirely. Often not decorated and with a simple ring to hold the suspension straps. Most common type, found on a variety of swords ranging from high quality to lower grade soldier's swords.