This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lower Extremity, Subject name: Anatomy
Which is not a cause of positive trendelenburg sign? 
Select and explain. 
A. Paralysis of gluteus maximus, B. Congenital dislocation of hip, C. Un-united fracture of neck, D. Coxa vara
A: Paralysis of gluteus maximus
Answer: A: Paralysis of gluteus maximus 
Explanation: Ans A Paralysis of gluteus maximusRef: Maheswari Orthopaedics, 5th ed. pg. 135* When a person stands on one leg, the tendency of unsupported side to sag down is counteracted by gluteus medius and minimus. These two muscles form the abductor mechanism of hip.* In case the abductor mechanism is defective, unsupported side of the pelvis drops and is called Positive Trendelenburg sign. It is seen in:# Paralysis of gluteus medius and minimus# Congenital dislocation of Hip# Ununited fracture# Coxa vara