What is the Pain in the Back of my Shoulder?

Your body is an intricate collection of tissues, each with a specific purpose and funciton. Pain, while an important sign of injury, does not necessarily tell a physicain what type of tissue is being affected. It could be very important to know whether the source of the pain is soft tissue (muscles, tendons, etc.), bone, or neurovascular (nerves and blood vessels). Quadrilateral space syndrome, which causes pain in the posterior shoulder, is an example of this important distinction.

The quadrilateral space, also referred to as the quadrangular space, is an anatomic space in the posterior shoulder. The space is bordered by the teres minor muscle (superiorly), teres major muscle (inferiorly), long head of the triceps (medially), and surgical neck of the humerus (laterally). Two important structures that course through the quadrangular space are the axiallary nerve and posterior humeral circumflex artery

Quadrilateral space syndrome, or impingment of the neurovascular structures in this space, can occur through a variety of mechanisms. Sometimes this syndrome presents with a gradual onset. Other times the syndrome occurs with acute injury, such as with a posterior shoulder dislocation. The patient will often described numbness in the affected extremity with poorly localized shoulder pain. Certain movements, such as raising the arm to the side, or rotating the shoulder outward can worsen the symptoms. If compression of the axillary nerve is not addressed there can eventually be wasting and atrophy of the deltoid muscle and subsequent weakness.

Surgery to decompression the affected area is an option, but only if the symptoms are persistent and severe. In most cases, conservative management is the best course of treatment. Pain relievers and anti-inflammatories can be prescribed to help control symptoms. Rest from provocative activities and application of ice can also be helpful. In some circumstances a patient may benefit from physical therapy to strengthen the shoulder muscles and increase flexibilty.

If you are experiencing shoulder pain, even without a history of injury or fall, we recommend being seen by Dr. Carfagno at your earliest convenience. Dr. Carfagno is board certified in both Internal Medicine and Sports Medicne, and is familiar with the presentation and workup of Quadrilateral space syndrome. He can both diagnose and treat your shoulder pain and get you back to your normal soon. 


Bryce Kirkman, MS-IV

David Carfagno, D.O., C.A.Q.S.M.



Redlar MR, Ruland LJ, McCue FC. Quadrilateral space syndrome in a throwing athlete. The American Journal of Sports Medicine. 1986;14(6), 511-3.

Brown DL, Chung KC. Quadrangular space syndrome associated with superficial radial sensory neuropathy. Annals of Plastic Surgery. 1999;43, 207-10.


Disclaimer:  Articles are based on real cases seen at Scottsdale Sports Medicine.  The information on this site is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. All content, including text, graphics, images and information, contained on or available through this web site is for general information purposes only. Please consult your medical professional for individualized healthcare.