"Patients with true radial head fractures/injuries of the elbow will find it very hard to externally oblique for the projection, it's best to encourage the patient to rotate from their shoulder. Therefore, not isolating the elbow joint, often this involves the patient leaning toward the side of obliquity."
"orientation "
"SID"
"patient's arm should be rotated externally more so than the AP projection so the radial head is free from superposition"