By now you may be asking yourself “how can every rib have associated health issues?”. My response: every condition anyone can get has to happen somewhere inside of the body, aka everything has a location. As with the sixth rib, the seventh rib is primarily associated with the liver and stomach. A lesion of the left seventh rib is primarily associated with the stomach while the liver will be affected by the rib on the associated side (the liver is big so it can be affected on either side).
The nerves associated with the seventh rib (if you are reading in order you can probably guess this): the seventh thoracic nerve with its anterior and posterior divisions, the sympathetic chain ganglia, the seventh thoracic sympathetic ganglion, the recurrent meningeal nerve, and the greater splanchic nerve.
The muscles that attach to the seventh rib are: serratus anterior, iliocostalis thoracis, iliocostalis lumborum, rectus abdominis, internal oblique, external oblique, transverse abdominis, the diaphragm, internal intercostal, and external intercostal. Note that the diaphragm attaches to the costal cartilage from the seventh rib downwards so the Operator should be mindful of doming the diaphragm as well as the associated functions of the respiratory pump.
The circulatory structures that are associated with the seventh rib are: the intercostal artery and vein, the azygos vein and the accessory hemiazygos vein, the thoracic lymphatic duct, the bronchomediastinal lymphatic ducts, as well as the hepatic and gastric vessels.
The effects of a lesion of the seventh rib are very similar to those of the sixth rib. Marion Clark does suggest that a lesion of the seventh rib does seem to have more deleterious effects on the venous structures due to the pressures exerted from a malpositioned rib as well as the increased sympathetic vaso-motor tone to the arteries that leads to circulatory congestion.
The seventh rib is the last of the true ribs as it has its own connection to the sternum. It is worth noting that it displays more costal cartilage than those above it. Although it has not been discussed earlier as it is a bit of a generalization, the seventh rib primarily displays a bucket handle movement. As a true rib there are likely more variations as to possible lesion presentations however it also has quite a bit of musculature that can keep it in an exhaled position (the abdominal musculature). If the abdominal musculature is in a relaxed state the seventh rib is more likely to stay inhaled.
As a treatment option the Operator is starting to run out of direct connections to the seventh rib via the arm (at least in the supine position) so the side-lying (think of the ribs as handles connecting the vertebrae and the sternum as well as the respiratory pump), prone (think arm rotations to correct the thoracic spine and thus the costo-vertebral joints), and seated (think of combined side-bending and rotation of the thoracic spine) positions may be more appropriate. As always there are uncountable combinations of correction options but the Operator must pay attention to the patient and the lesion as they present.