<prompt> The position of arm in posterior dislocation of shoulder is:By the sideIn internal rotationIn adductionIn external rotation  <response>: Position of arm in posterior dislocation of shoulder It is difficult to diagnose because the patient may have normal contour of shoulder. Patient holds the injured shoulder in internal rotation and examiner cannot externally rotate it. Ref: Rockwood and Greens Fractures in Adult 6e, Page 1285-1300. 