A 3629-g (8-lb) newborn is examined shortly after spontaneous vaginal delivery. She was delivered at 40 weeks' gestation and pregnancy was uncomplicated. Her mother is concerned because she is not moving her left arm as much as her right arm. Physical examination shows her left arm to be adducted and internally rotated, with the forearm extended and pronated, and the wrist flexed. The Moro reflex is present on the right side but absent on the left side. Which of the following brachial plexus structures is most likely injured in this infant?
- A)Upper trunkGABARITO
- B)Long thoracic nerve
- C)Lower trunk
- D)Axillary nerve
- E)Posterior cord
Explicação
This infant's "waiter's tip" position (arm adducted, internally rotated, forearm extended and pronated, wrist flexed) with absent Moro reflex on the affected side indicates Erb palsy — injury to the upper trunk (C5-C6) of the brachial plexus. The upper trunk c... Ver explicação completa e trilha adaptativa →