A 12-year-old boy is diagnosed with an upper brachial plexus injury after falling from a tree. He presents with his right upper arm lying limp at his side because of loss of abduction. Which of the following muscles are primarily responsible for abduction of the arm at the shoulder?
A、Deltoidandbicepsbrachii
B、Deltoidandsupraspinatus
C、Deltoidandinfraspinatus
D、Supraspinatusandinfraspinatus
E、Coracobrachialisandsupraspinatus
发布时间：2024-09-26 12:23:30
