• The nerve supply to pronator muscle of distal radioulnar joint is?
  A. Median nerve
  B. Ulnar nerve
  C. Posterior interosseous nerve
  D. Anterior interosseous nerve
  
  Ans: D) Anterior interosseous nerve
  
  Explanation -

Pronation:

Nerve root responsible for the movement - C7,C8

Muscles responsible -
   1) Pronator Quadratus, assisted by
   2) Pronator teres
   3) Flexor carpi radialis
   helped by Gravity

So, Pronator Quadratus is the main pronator of the distal radioulnar joint

Nerve Supply of Pronator Quadratus - Anterior Interosseous nerve (A branch of Median nerve)

Nerve Supply of Pronator Teres - Median nerve (before the median nerve passes between the two heads of this muscle)

Nerve Supply of Flexor Carpi Radialis - Median nerve