The shoulder tip is located where the top of the arm and the edge of the shoulder meet, forming a bony angle that is bound by the armpit along the bottom side. Shoulder tip pain is associated with internal injuries to the abdomen, especially ectopic pregnancy and spleen rupture.
The shoulder tip is not especially prone to injury itself, but references to it often appear in medical literature as an example of referred pain. Referred pain is pain that is experienced distantly from the site of injury. Although located relatively far from any major internal organs, the shoulder often aches when these organs become injured. This is because the nerves of the shoulder originate from the same main branch that also enervates many internal organs. When the shoulder tip in particular aches in response to internal injury, it is called Kehr's sign. Pain in the left shoulder tip is associated with a ruptured spleen.