Question
Is there a range of motion test performed on physical examination which is referred to as: Drop Arm, Empty Can, and Arc, or also referred to as drop, can, arc?

Answer
I believe that the test you are referring to is what we called the 'empty beer can test' in school.  This is an orthopaedic test, not a range of motion test, however. It is performed by placing the arm straight out from the body (to the side) and bringing it 15 degrees forward.  By puttin the thumb down, just like you are trying to get the last drops out of a can, you are effectively in a position to test the supraspinatus muscle of the rotator cuff.  It is further tested by applying pressure to the arm in a downward motion.

I hope this helps.

Dr. P