This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Acute Appendicitis, Subject name: Surgery
Hyperextension of hip producing pain in acute appendicitis is due to which muscle? 
Select and explain. 
A. Gluteus maximus, B. Obdurator Extemus, C. Psoas Major, D. Quadratus lumborum
C: Psoas Major
Answer: C: Psoas Major 
Explanation: Ans. is 'c' i.e., Psoas Major - o In retrocecal appendicitis, inflammed appendix is in contact with psoas muscle causing flexion of the hip joint. Hyperextension of the hip joint may induce abdominal pain. This is known as 'iliopsoas sign' and is typical of retrocecal appendicitis.Other signs seen in appendicitis:o Obturator sign: pain on internal rotation of the hip (suggesting a pelvic appendix)o Dunphy's sign: Any movement, including coughing (Dunphy's sign), may cause increased paino Rovsing's sign: pain in the right lower quadrant during palpation of the left lower quadrant.