Shoulder Impingement: Part 4 – The Thoracic Spine and Ribcage’s Role in Impingement

source: eorthopod.com

source: eorthopod.com

So far we’ve gotten pretty deep on the concept of shoulder impingement but it’s time to delve a little deeper.  Next in the line-up we’ll talk about the thoracic spine and ribcage.  If you missed the previous parts you can find them here:

Part 1  Part 2  Part 3

Updated November 2017

If we take a closer look at the shoulder joint and scapula we’ll notice that we only have 1 true joint that connects the shoulder to our trunk.  The scapula attaches to the clavicle at the acromioclavicular joint and the clavical attaches to our thorax via the sternum at the sternoclavicular joint. These two relatively small joints are the only real joints that connect our arm to our trunk.

Side Note: There is quite a bit of motion that occurs in the SC and AC joints with overhead motion.  We tend to forget these joints in favor of the bigger more popular joints.  Myself and colleagues have anecdotally had some luck with manual mobility to these regions to decrease pain and improve ROM overhead with our athletes but take this with a grain a salt given it is not evidence based…

source: conornordengren.com

source: conornordengren.com

There is also a connection between the scapulae and the posterior element of our ribcage as seen to the right.  Although this is not a true joint we refer to this connection as the scapulothoracic joint.  The scapula lies directly on top of our rib cage and slides smoothly across the surface of the ribs during shoulder movement.  Because of this, efficient and healthy movement at the scapulothoracic joint has everything to do with the orientation of the ribcage that the scapula slides along.  If the position of our ribcage is potentially off, it will change the position of our shoulder blades and as described later, can potentially lend itself to impingement.

Our spine consists of a series of vertebrae stacked on top of each other that extend from the base of our skull down to our sacrum (and a bit lower to our coccyx).  The vertebrae that make up our neck are known as cervical vertebrae. The vertebrae in our trunk that attach to our ribs are known as thoracic vertebrae and the vertebrae that make up our lower back are known as lumbar vertebrae.  As mentioned previously, the vertebrae in our thoracic spine attach to the ribs.   Because of this, the orientation of our ribcage is directly related to the mobility of our thoracic spine (and subsequently the orientation of the shoulder blade and shoulder joint)

Food for thought: The thoracic spine’s attachment to the ribs creates quite a bit of stability.  This can make it difficult to gain mobility in the thoracic spine when we need to.

Thoracic spine mobility (extension), posterior tilting of the scapula and overhead motion are also synonymous.   Understanding this concept can be difficult.  Think of it this way.  As we raise our arms overhead the scapula is supposed to ride flat along the thoracic spine.   In healthy overhead motion the scapula will upwardly rotate, elevate and posteriorly tilt.  In order to posteriorly tilt properly, the ribcage must create an optimal surface to allow this motion.  Adequate thoracic extension creates a more optimal ribcage surface to allow the scapula to do it’s job and get our arms overhead safely and efficiently.  If we have a large kyphosis and decreased ability to extend at the thoracic spine, the surface of the ribcage will make overhead motion much more difficult.

Now here’s a little experiment to help explain the above details.  Stand with poor posture with your shoulders and head forward with a big round in your upper back.  Keep this posture and try to raise your arms overhead as much as you can.  Not too good huh?

Now fix your posture.  Pull back your shoulders and tuck your chin.  Straighten up your upper back.  Now reach overhead again.  Better?  If we’re lacking thoracic spine extension range of motion it’s going to make healthy efficient overhead motion impossible.

source: www.ericcressey.com

source: www.ericcressey.com

On top of that, normal overhead elevation of the shoulder is only 165-170 degrees(4).

165 degrees does not get our arms completely overhead.  We’ll need full range of motion for all exercises that requires us to press weight overhead (Military Press, Push Press, Push Jerk etc).  Our body achieves those last few degrees of overhead motion with thoracic spine extension and scapular posterior tilt.

Side Note: To add insult to injury, a lack of overhead flexibility can cause a compensation somewhere down the chain in order to get our arms completely overhead.  Often times we try to achieve extra motion by extending our lumbar spine.  (Anyone else smell lower back pain?)

Having adequate motion from the thoracic spine (extension) and scapula (upward rotation and posterior tilt) not only allows us to get our arms fully overhead but also increases subacromial space in the shoulder.  As discussed previously, compression of the subacromial contents is our theory of how subacromial impingement occurs.  Having more space when exercising is probably a good thing.  With these concepts in mind it’s already sounding like proper thoracic spine and rib mobility is important for shoulder health but there is also another concept to understand on our quest for optimal shoulder health.

In our shoulders, as we raise our arms overhead and reach end range of motion (flexion) the subacromial space in the shoulder decreases.  This occurs because the greater tuberosity of the shoulder is getting closer to the acromion.

As you can see, when you bring your arms overhead the subacromial space decreases and the subacromial contents (rotator cuff, biceps tendon and bursa) are compressed in the process.  Now this is a normal occurrence for healthy shoulders and shouldn’t be something to worry about.  However if you’re an overhead athlete who very regularly loads weight overhead it might become an issue for you.

source: www.dynamicchiropractic.com
source: www.dynamicchiropractic.com

Clinically I see a lot of impingement patients with pain at end range of flexion (bringing their arms fully overhead).  What may be happening with these folks is that they’re getting compression of the rotator cuff at the end range of motion (As shown in the images above).  If they overload the tendons with excessive exercise (above what their shoulder is able to tolerate via push press, bench press, push jerks, pull-ups, snatch etc.) sometimes the tendons get irritated.  Now end range shoulder flexion is tender.

A common clinical test is known as the Neer’s test and is a test for subacromial impingement.  It’s basically designed to bump the greater tuberosity against the acromion and pinch the rotator cuff and biceps tendon.  These folks also tend to have positive Neer’s tests.

Our current theory for the mechanism of rotator cuff injury is a combination of compressive and tensile overload to the tendon.  If we’re sending the compressive forces through the roof we might be increasing our chances of injuring these structures (especially with a lack of preparation of the rotator cuff and scapular musculature).

Here’s how you can assess thoracic spine extension:

Click HERE for an article with a boatload of great thoracic spine mobilization ideas

On top of this information there is quite a bit of research to show that thoracic spine and rib mobilizations can be helpful (improving range of motion, pain levels and global ratings of change) for people who have shoulder pain and or shoulder impingement syndrome (atleast in the short term).

Sidenote: It is important to note that manual manipulation of ribs and thoracic spine does tend to increase overhead range of motion but does not tend to change scapular dyskinesia.  Our current theory as to why this is happening is due to neurophysiologic processes (a fancy term to mean that we’re changing pain sensitivity and the nervous system) and not just biomechanical (changing the orientation of the ribs and spine) reasons.  

Well, there’s the details on the thoracic spine and ribs.  If you’d like to learn more about the specific manual techniques for shoulder pain check out the works cited section below.  I think I’ve strained my brain enough writing about this topic.  Give me some time to ice my brain and I’ll get back to you next week with more shoulder goodness.  Until then…

Part 5 HERE

Want to learn more about how to rehabilitate and prevent future shoulder injury?  Check out my latest shoulder course with Dr. Dave Tilley.

Just a few things covered in the course…

  • Functional Shoulder Anatomy: What parts of the shoulder are most relevant to your understanding of injury and performance?
  • The Most Common Shoulder Injuries Seen in the Gym: Shoulder impingement, rotator cuff tears, biceps tendonitis, AC joint injuries, bursitis and labral tears
  • Technical Errors: Advice on where injuries occur in the major lifts and how to fix this
  • Advanced Rehabilitation Strategies: Learn how to bridge the gap between basic rehabilitation and high level performance
  • Progressive Return to Exercise Programs – Specific exercise protocols to help you return back to pull-ups, bench press, muscle-ups, snatching, jerks and overhead pressing

Click HERE to Learn More about Peak Shoulder Performance

Rotary cups of steel,

Dan Pope DPT, OCS, CSCS CF L1

Resources:

1. Meurer, A., Betz, U., Decking, J., & Rompe, J. (2004). [bws-mobility in patients with an impingement syndrome compared to healthy subjects–an inclinometric study]. Z Orthop Ihre Grenzgeb,144(4), 415-420. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/15346302

2. Lukasiewicz AC, McClure P, Michener L, et al. Comparison of 3-dimensional scapular position and orientation between subjects with and without shoulder impingement. J Orthop Sports Phys Ther. 1999;29:574–583.

3. McClure, P., Michener, L., & Karduna, A. (2006). Shoulder function and 3-dimensional scapular kinematics in people with and without shoulder impingement syndrome. Physical Therapy86(8), 1075-1090. Retrieved from http://ptjournal.apta.org/content/86/8/1075.full

4. Gulick, D. (2009). Ortho notes. (2nd ed., p. 189). Philadelphia, PA: F.A. Davis Company.

5. The Immediate Effects of Thoracic Spine and Rib Manipulation on Subjects with Primary Complaints of Shoulder Pain Joseph B. Strunce, PT, DSc, OCS, FAAOMPT,a, Michael J. Walker, PT, DSc, OCS, FAAOMPT,b Robert E. Boyles, PT, DSc, OCS, FAAOMPT,c and Brian A. Young, PT, DSc, OCS, FAAOMPTd . 2009; 17(4): 230–236. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813499/

6. The Effects of Thoracic Spine Manipulation in Subjects With Signs of Rotator Cuff Tendinopathy http://www.jospt.org/doi/pdf/10.2519/jospt.2012.4142?code=jospt-site

7. CHANGES IN SHOULDER PAIN AND DISABILITY AFTER THRUST MANIPULATION IN SUBJECTS PRESENTING WITH SECOND AND THIRD RIB SYNDROME James Dunning, DPT, MSc, a Firas Mourad, PT, OMT, Cert. SMT, b Giuseppe Giovannico, PT, MSc, OMT, c Filippo Maselli, PT, MSc, OMT, d Thomas Perreault, DPT, Cert. SMT, Cert. DN, e and César Fernández-de-las-Peñas, PT, DO, PhD, DMSc https://www.spinalmanipulation.org/dbmedia/Rib%202-3%20Syndrome%20Dunning%20et%20al%202015.pdf

8. REBEKAH L. LAWRENCE, PT, DPT, OCS1 • JONATHAN P. BRAMAN, MD2 • ROBERT F. LAPRADE, MD, PhD3 • PAULA M. LUDEWIG, PT, PhD1,4 Comparison of 3-Dimensional Shoulder Complex Kinematics in Individuals With and Without Shoulder Pain, Part 1: Sternoclavicular, Acromioclavicular, and Scapulothoracic Joints  http://www.jospt.org/doi/pdf/10.2519/jospt.2014.5339

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