Anatomy, anatomy, anatomy…the Osteopath’s most important ally! Anatomy is a never-ending exploration for myself and, hopefully, all current and future Osteopaths. The ability to be able to connect seemingly divergent areas in the body to provide solutions to health issues people face requires an in depth knowledge of anatomy…this is said often enough, so let us now illustrate one such POSSIBILITY.
A shoulder problem is often not simply a shoulder problem – I have shown how the arm is connected to the abdominal musculature and, by extension, to the pelvis. The connection to the pelvis is an important one for the Osteopathic Operator as a lesioned pelvis can be the sole cause of a shoulder problem (or simply a part of the problem). To extend the anatomical connections further than the iliac crest and linea alba I will highlight the connection of the sacrum to the arm.
Enough preamble – down to business. The superior end of the connection is at the floor of the intertubercular sulcus (bicipital groove) at the “insertion” of the latissimus dorsi. The latissimus dorsi then travels to connect to ribs 10-12, spinous processes from D12-L5 as well as the median sacral crest (aka spinous processes of the sacrum), as well as the iliac crest. Aside from the bicipital groove, the latissimus dorsi blends in to the thoracolumbar fascia as its anchor to the bony structures previously noted. Luckily, this is a very simple line! What does it mean though? When the sacrum goes in to lesion, for whatever reason, it is very likely that the latissimus dorsi will show an effect on some level. The latissimus dorsi will also show effects from alterations in the lumbar curve (in any plane) as well as ribs 10-12 directly and POSSIBLY ribs 6-9 via the costal cartilage shared down to rib 10. Due to the positioning of the latissimus dorsi on the humerus it can lead to malposition of the humeral head in the glenoid fossa – this would LIKELY be seen as a humeral head that is anterior/superior/and externally rotated (this is not an absolute statement as there are other variables at play) if the latissimus dorsi was in a shortened state.
Through the connections to the vertebral column the latissmus dorsi is going to be involved in vertebral mechanics on some level – the degree to which the involvement occurs will depend on the individual. Back to the initial idea though – the sacrum is quite clearly connected to the arm via the latissimus dorsi. The multiple other connections that run from the sacrum to other points of the body then have the opportunity to influence the arm through the sacrum as a junction point of sorts – ie a lesioned sacrotuberous ligament/hamstring can alter sacral mechanics which can then alter shoulder mechanics (and vice versa of course). It is through these lines of thinking that it must be clear that the body is ONE continuous unit that is interconnected on all levels. The solution to the shoulder problem might be in the sacrum or it might be passing through the sacrum – remember to check ALL structures to find the real solution.