This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Orthopaedics
"Trendelenburg sign" isn't positive in damage of the following nerve 
Select and explain. 
A. Inferior gluteal nerve, B. Pudendal nerve, C. Superior gluteal nerve, D. Posterior tibial nerve
C: Superior gluteal nerve
Answer: C: Superior gluteal nerve 
Explanation: Causes of positive trendelenberg test: *There are three fundamental causes: 1) Paralysis of the abductor muscles *eg. Polio *Paralysis of superior gluteral nerve 2) Marked approximation of the inseion of the abductor muscle to their origin by upward displacement of the greater trochanter; so that muscles are slack. *eg. Severe coxa vara *Dislocation of hip 3) Absence of stable fulcrum & lever arm about which the abductor muscles can act *Neck femur fracture *Dislocation of hip :Ref: Maheshwari 4th/e p.348