The winged scapula syndrome is an uncommon cause of pain in the back.  The scapula is a large bone located on the upper back and is part of the shoulder.  There are numerous muscles attached to the scapula which helps to move and stabilize the shoulder joint.  Winging of the scapula occurs when the blade of the scapula bone protrudes backward.  The cause of this problems is commonly injury to the long thoracic nerve which controls the serratus anterior muscle.  Less commonly, injury to the spinal accessory nerve can cause paralysis of the trapezius and injury to the dorsal scapular nerve can cause injury to the rhomboid.  Both of these mechanisms can result in scapular winging.  Injury to these muscles can be debilitating, causing difficulty in lifting and pulling and limiting every day activities.  The most common cause of winged scapula syndrome is trauma, but other causes may include viral infections as well as brachial plexus or cervical spinal injury.  The pain of winged scapula syndrome is usually located in the shoulder and radiates down the arm or into the back.  There may be weakness of shoulder motion.  Having the patient press his outstretched arm against a wall will easily demonstrate the winging of the scapula.  Testing involves X-rays and MRI of the shoulder to exclude other causes of pain.  Electromyography and Nerve Conduction Studies will delineate the lesion.  There is no specific treatment for Winged Scapula Syndrome.  Pain can be treated by simple analgesics such as non-steroidal anti-inflammatories.  A certain percentage of these injuries will spontaneously recover within 24 months, depending on the cause of the problem.  Physical therapy modalities such as bracing may be useful as well.