A 23-year-old male presents to clinic with 2 days of left sided low back pain. The patient states the pain began after he got tackled during a recreational football game with his friends. He has tried over-the-counter pain medications with moderate relief but is worried that he might have broken his ribs. Physical examination reveals tenderness to palpation on the right flank around ribs 7-12. Osteopathic structural examination reveals decreased range of motion of ribs 7-12. Xray imaging completed in the office shows all ribs to be intact. Osteopathic treatments begin with focus on the serratus anterior muscle. Which of the following is the key rib and the somatic dysfunction the patient is exhibiting?