Introduction

Burners and stingers are acute traction injuries of the brachial plexus that are characterized by a burning and stinging pain running from the shoulder to the hand.^1-7 Injuries of this type are most commonly associated with contact sports, such as football, and are most often seen in adolescents and young adults.^1,5 In addition to pain, associated weakness in shoulder abduction, elbow flexion, and external humeral rotation are also present. Because the brachial plexus is the only nervous structure involved, pain and weakness are not commonly found in the lower extremities.

Incidence and Epidemiology

Burners and stingers are common injuries seen in patients who participate in sports that involve tackling. They are seen more often in males than females, and in children, adolescents, and young adults. Burners and stingers are one of the most common injuries in football, as studies have shown that 49% to 65% of college football players recall having symptoms during their careers.^1,3,4,6-8 Risk factors for burners and stingers include involvement in contact sports, motorcycle riding, and preexisting cervical stenosis.

Clinical Features

The most common symptom of traction injuries to the brachial plexus is a burning and stinging sensation in the arm, as well as numbness and tingling. The distribution of the pain and numbness depends on the exact location of the injury in the cervical spine and brachial plexus. The upper trunk of the brachial trunk is most commonly affected, resulting in weakness in shoulder abduction (C5/deltoids), elbow flexion (C6/biceps), and external humeral rotation (C5-C6/supraspinatus and infraspinatus).¹

Physical Examinations

The physical examination of a patient with suspected burners and stingers includes several steps. First, palpation for tenderness of the cervical spine should be performed.¹ In addition, testing the range of motion associated with the cervical spinal nerves is important because deficiencies may signal a serious condition.¹ A complete neurological examination must be performed in the upper and lower extremities for sensation and strength.¹ Any weakness in the extremities should be noted. Palpation of brachial plexus in the axilla should also be performed. A positive Tinel's sign in the brachial plexus indicates damage to more than one nerve.¹

Cervical instability is appreciated with plain radiographs of the cervical spine with flexion and extension views. The Torg ratio is calculated based on an extension lateral cervical spine radiograph. The ratio is determined by dividing the distance between the midpoint of the posterior aspect of the vertebral body to the nearest point on the corresponding spinolaminar line by the anteroposterior width of the vertebral body (Slide).

Slide

Meyer and colleagues demonstrated that a Torg ratio <0.8 in college athletes caused a threefold increase in sustaining burners with cervical spine-extension-compression type injuries.⁹ Magnetic resonance imaging (MRI) of the cervical spine is used to assess for injuries of the cervical spinal cord.^1,8

Laboratory studies such as nerve conduction velocity tests and electromyogram are necessary only in situations in which neurological function does not return to normal by 3 weeks. Symptoms occurring for more than 1 week are typically associated with greater traction of the brachial plexus.^1,3-5 These studies should not be used to determine whether athletes can return to full activity.^1,10

Pathophysiology

Burners and stingers result from compression of the nerve root or traction or compression of the brachial plexus.^6,7 Symptoms of burners and stingers typically result from depression of the ipsilateral shoulder and deviation of the neck to the contralateral side.⁶ These symptoms commonly occur in motorcycle accidents or contact sports such as football, where tackling might cause a direct blow and traction to the ipsilateral supraclavicular region.^1,3 Acute disk herniation is not commonly a cause of acute burners and stingers syndrome but may contribute to recurrent burners and stingers syndrome.³

Radiographic Features

Signs of burners and stingers are rarely seen in radiographs or MRIs. Plain radiographs are used to evaluate for cervical instability and any injury to the cervical nerve root foramina. Radiographs should be used to rule out cervical spine injury and stenosis. An extension lateral cervical radiograph is used to determine the Torg ratio. If the Torg ratio is <0.8, cervical spinal stenosis may be present.²

Treatment

Symptoms of burners and stingers syndrome usually last several minutes to several hours, rarely longer.^1,2,8,10 Treatment involves addressing predisposing factors, management of acute symptoms, and prevention of future insult to the nerve structures.¹

Individuals with upper extremity stiffness and weakness are at greatest risk for acute traumatic injuries to the brachial plexus. Therefore, aside from proper use of protective equipment (e.g., neck guards), patients should increase strength and flexibility of the upper body to prevent burners and stingers.^1,2,8 If these injuries are recurrent, then the patient should eliminate the activity responsible for them or correct sports technique to limit the risk of occurrence.

In treating existing symptoms of burners and stingers, it is important to restore pain-free mobility in the upper extremities by strengthening and stretching.¹ When not in use, the affected arm can be placed in a sling for comfort. Over-the-counter analgesics can be used as needed.¹ Return to full activity is warranted only when full mobility and strength have returned, and pain and neurological symptoms have completely resolved.^1,4 Follow-up in all cases of burners and stingers, regardless of the duration of symptoms, is important.⁴ Return to play criteria are summarized in the following table:

In patients with prolonged symptoms of burners and stingers lasting days to weeks, additional evaluation is important. Radiographic assessments of the cervical spine, including flexion/extension views should be made to check for stability.

References

1. Safran MR. Nerve injury about the shoulder in athletes, Part 2: Long thoracic nerve, spinal accessory nerve, burners/stingers. Am J Sports Med. 2004; 32:1063-1076.
   
    
2. Weinberg J, Rokito S, Silber JS. Etiology, treatment, and prevention of athletic "stingers". Clin Sports Med. 2003; 22:493-500.
   
    
3. Levitz CL, Reilly PJ, Torg JS. The pathomechanics of chronic, recurrent cervical nerve root neurapraxia. The common burner syndrome. Am J Sports Med. 1997; 25:73-76.
   
    
4. Clancy WG Jr, Brand RL, Bergfield JA. Upper trunk brachial plexus injuries in contact sports. Am J Sports Med. 1977; 5:209-216.
   
    
5. Robertson WC Jr, Eichman PL, Clancy WG. Upper trunk brachial plexopathy in football players. JAMA. 1979; 241:1480-1482.
   
    
6. Kelly JD 4th, Aliquo D, Sitler MR, Odgers C, Moyer RA. Association of burners with cervical canal and foraminal stenosis. Am J Sports Med. 2000; 28:214-217.
   
    
7. Watkins RG. Neck injuries in football players. Clin Sports Med. 1986; 5:215-246.
   
    
8. Feinberg JH. Burners and stingers. Phys Med Rehabil Clin N Am. 2000; 11:771-784.
   
    
9. Meyer SA, Schulte KR, Callaghan JJ, et al. Cervical spinal stenosis and stingers in collegiate football players. Am J Sports Med. 1994; 22:158-166.
   
    
10. Speer KP, Bassett FH. The prolonged burner syndrome. Am J Sports Med. 1990; 18:591-594.