1. Sit at a flat table or workbench with your forearms straight, palms facing down on the table, and with your elbows resting against the side of your body,
2. Measure the angle of the straight line between your elbow joints and the upper side of your forearms using an angle gage (you can also use a piece of paper and a straightedge),
3, Place the angle gauge on your arm so that it is parallel to your forearm, making sure that the angle gauge's baseline is in natural contact with your arm.