Keep your elbow stuck on your side. Then push your hand outward while keeping your elbow close to your body. Do you feel any pain?
Now if you felt pain, rotate your forearm like you did before up until it starts hurting. Then push your elbow away from your body while keeping your hand at in the same position. Do you feel less pain that way?
Normally, you should feel less pain pushing your elbow than rotating your forearm. At least that's what I've seen happen but I'm no doctor.
