How to sense shoulder movement

Hello, today i am wondering how to sense shoulder movement. i am planning on putting something on the bicep. Preferably i would like to use an accelerometer to measure the movement of the shoulder but i am also willing to pay more for a gyro. please tell me which one will be the better choice for the job.

Thank You!

You're trying to measure a shrug, a rotation, a trying-to-muscle-into-a-queue...what?