Quadrilateral Space Syndrome

ExitCare ImageQuadrilateral space syndrome is a rare condition affecting the nervous system in the shoulder. This condition is caused by the compression of the axillary nerve. The axillary nerve connects the deltoid muscle. The deltoid muscle is the primary muscle of the shoulder. There is a space in the back of the shoulder formed by:

  • Three muscles (teres minor, teres major, triceps).

  • One bone (humerus).

The axillary nerve runs through this space. This is where the axillary nerve is often compressed causing the symptoms.


  • Pain and discomfort, often in the back of the shoulder.

  • Pain occasionally in the front of the shoulder and arm.

  • Heaviness or fatigue of the arm.

  • Pain made worse by putting the arm in the thrower's position.

  • Sometimes, tingling, numbness, or burning in the back of the shoulder and occasionally the arm and forearm.

  • Tenderness in the back of the shoulder.

  • Shrinkage of the deltoid muscle or teres minor muscle.


Pressure placed on the axillary nerve in the back of the shoulder.


  • Contact sports.

  • Sports that require throwing (baseball pitchers).

  • Poor strength and flexibility.


  • Warm up and stretch properly before activity.

  • Maintain appropriate conditioning:

  • Shoulder flexibility.

  • Muscle strength and endurance.


This condition is usually curable with appropriate treatment. Sometimes surgery is necessary.


  • Permanent weakness of the shoulder, especially in throwers position (when rotating arm outward, lifting the arm, and throwing).

  • Persistent pain in the shoulder.

  • Increasing weakness of the extremity.

  • Disability and inability to compete.


Treatment includes stopping activities that make the symptoms worse. Ice and medicine will help reduce pain and inflammation. It may be helpful to complete strengthening and stretching exercises. To complete these exercises, you may be referred to a therapist. Treatment to help reduce inflammation may also include:

  • Ultrasound therapy.

  • Injections of corticosteroids.

If non-surgical treatment is unsuccessful, then surgery may be necessary. Surgery involves cutting the soft tissue that is compressing the nerve. Surgery typically provides complete resolution of symptoms.


  • If pain medicine is necessary, then nonsteroidal anti-inflammatory medicines, such as aspirin and ibuprofen, or other minor pain relievers, such as acetaminophen, are often recommended.

  • Do not take pain medicine for 7 days before surgery.

  • Prescription pain relievers are usually only prescribed after surgery. Use only as directed and only as much as you need.

  • Injections of corticosteroids may be given to reduce inflammation.


  • Cold treatment (icing) relieves pain and reduces inflammation. Cold treatment should be applied for 10 to 15 minutes every 2 to 3 hours for inflammation and pain and immediately after any activity that aggravates your symptoms. Use ice packs or massage the area with a piece of ice (ice massage).

  • Heat treatment may be used prior to performing the stretching and strengthening activities prescribed by your caregiver, physical therapist, or athletic trainer. Use a heat pack or soak the injury in warm water.


  • Symptoms get worse or do not improve in 2 weeks despite treatment.

  • New, unexplained symptoms develop (drugs used in treatment may produce side effects).