I'm working for about 2 months to build a system for getting digitally values about the angle of the elbow. The project is designated to create a large usage tool and that's why it's preferably to use mechanical staff that are comfortable for the 'user' and to not look very peculiar. It is not compulsory to get directly the angle because if I get for instance the distance between hand and shoulder it's easy afterwards to transform it in angle. I have some options using mouse encoders but implemented on the body but they look too strange and its too much mechanic.
If you have any suggestions/ideas please type them here, any response is welcome !