Here's a fun, low-fi way of motion capturing finger movement.
Islam Almusaly writes:
If you own an iPad, then I have good news for you. You can visit the following URL to capture your fingers motion by touching you screen. Then you can import it to Blender.
I created this project for my masters 4 years ago. It worked only on first generation iPad. Know, I wanted to give back to the Blender community. I rewrote the code to work to work as a webapp. I never tested it on other touchscreen devices but I think it should work. It is still in its beginning but I hope you will find it useful. You can use the imported animation to move anything not just fingers or bones.