It’s common when working with shoulder or thoracic spine pain patients to get confused as to why our interventions quickly improve patient’s function, or why the same presentation in another patient doesn’t budge with the same intervention. There are many biomechanical reasons for why our intervention didn’t get the results we were looking for, as well as variables we don’t wholly understand ( ex. patient just doesn’t feel comfortable in the environment).
Bill Hartman has eloquently introduced the concept that the patient should be treated from a bottom to top approach, and Zac Cupples provides a fantastic functional anatomy description as to how to start applying this concept.
If a patient is not achieving any changes in their shoulder range of motion, or trunk rotation then the lower thoracic spine and lower rib cage should be addressed first.
When we take a breath in, the bottom of our lungs fill up first much like a cup of water fills from the bottom up. You can’t try and fill a glass in the middle or top first.
The bottom of the rib cage is also much more flexible than the top due to the long costal cartilage connections of ribs 7-10, and the diaphragm itself increases the lateral expansion of the rib cage in the lower region.
If someone is lacking full respiratory motion in the lower rib cage, then the body will have to use a new way to move air in and out of the upper thorax. This typically looks like increased superficial muscle compression to help lift the rib cage cranially (using neck muscles), and using anterior/ posterior compression of the trunk to push air out (because hey… we have to keep breathing).
This compensatory mode of breathing creates 2 problems:
- Muscles that need to eccentrically orient to allow for full shoulder motion can not due to being required to assist with respiration.
- Decreased rib cage movement affecting scapulothoracic motion.
If you’re struggling to improve shoulder range of motion, or decrease thoracic spine pain (with the absence of more serious internal pathology) consider trying to increase the dynamics of the infrasternal angle (and infrapubic angle, but we’ll leave that for another day).