A newborn girl has an Apgar score of 7-8 points at the 1-5 minutes after birth. During the labor there was a brief difficulty with extraction of the shoulder girdle. After birth the baby presents with disturbed function of the proximal segment and forced position of the right arm. The shoulder is inwards, the elbow is extended, the forearm pronated, and the whole upper limb resembles the arm of a doll. What is the most likely clinical diagnosis in this case?