History and Physical Exam
History reveals a high impact mechanism or a fall in the elderly. On exam, look for leg length discrepancy. The pelvis will be tender and may feel unstable. The stability of the pelvis can be assessed by compressing both iliac crests medially. This will elicit pain and the examiner may feel pelvic motion.
It is not recommended to vigorously "rock" on the pelvis, compress posteriorly (which will open the pelvis further), or to perform repeat exams.