Chiro.Org Blog:

Upper-thoracic spasms and trigger points are common within the milder complaints heard in a chiropractic office. Typical posttraumatic injuries of the posterior thorax involve the large posterior musculature, thoracic spine, spinocostal joints, and tissues supporting and mobilizing the scapula (especially the rhomboids). Upper right abdominal quadrant ailments (eg, gallbladder, liver) commonly refer pain and sometimes tenderness to the right scapular area.