This is a simple test to figure out if you're using your smartphone a tad too much. It's called the Eichoff's Test, and its purpose is to test for De Quervain's syndrome, or also more commonly known as smartphone thumb. Or BlackBerry thumb. Or Gamer's thumb. It's quite simple too.

De Quervain's syndrome is a form of tenosynovitis, which is a repetitive strain injury caused by frequent use of thumbs to press buttons. Check it out below: