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 rib 12. The patient also exhibits restriction of motion of rib 12 upon deep inhalation. Xray imaging completed in the office shows all ribs to be intact. Given the physical exam findings, which muscle should osteopathic treatment be focused towards to correct the patient’s somatic dysfunction?