A 78-year-old female tripped and fell while walking.

An externally rotated, shortened leg is a classic sign of a proximal femur fracture, specifically a femoral neck or intertrochanteric fracture, commonly seen in elderly fall patients. This presentation reflects muscle pull and fracture displacement.

Posterior hip dislocations cause internal rotation.

Pelvic fractures may cause instability but not specific leg rotation/shortening.

Colles ' fracture is a distal radius (wrist) injury, unrelated to leg trauma.