An X-ray of the arm is a safe and painless test to visualise the arm using small amount of radiation. The area of the arm includes the shoulder joint, bone of the upper arm (humerus), elbow, bones of the forearm (radius and ulna), the wrist and the soft tissues (skin and muscles) surrounding it. The image is recorded on a special X-ray film. The X-ray image is black and white. Dense structures such as the bones, appear white and softer body tissues, such as the skin and muscles appear darker. The actual exposure time to radiation is usually less than a second, although the overall test may take 15-20 minutes.