As VIc and others stated, this could be a bad'un, go get it fixed, the quicker the better, and it is gonna hurt like hell, but the longer you put it off the worse it will get and you may lose some flexibility, etc later in life. You have torn the muscle, it will greatly affect your ability to turn a screwdriver with any strength, and will not get better if it is so bad that it really needs surgery.
Numismaniac wrote: