Anatomy and Evaluation of the Brachial Plexus San Jose State University Undergraduate Athletic Training Educational Program

Contents Anatomy of the Brachial Plexus Anatomy of the Brachial Plexus Mechanisms of Brachial Plexus Injury Mechanisms of Brachial Plexus Injury and Pathologies Neurological Evaluation for the Brachial Plexus and Related Special Tests Neurological Evaluation for the Brachial Plexus and Related Special Tests

Anatomy

Levels R oots R oots T runks T runks D ivisions D ivisions C ords C ords B ranches B ranches R eal R eal Athletic T rainers Athletic T rainers D rink D rink C old C old B eer B eer

Brachial Plexus Branches & Muscular Innervations Dorsal Scapular N. Levator Scapulae Levator Scapulae Rhomboid Major/Minor Rhomboid Major/Minor Lateral Pectoral N. Pectoralis Major/Minor Pectoralis Major/Minor Suprascapular N. Infraspinatus Infraspinatus Supraspinatus Supraspinatus Musculocutaneous N. Biceps Brachii Biceps Brachii Brachialis Brachialis Coracobrachialis Coracobrachialis

Brachial Plexus Branches & Muscular Innervations Axillary N. Deltoid Deltoid Teres Minor Teres Minor Upper Subscapular N. Subscapularis Subscapularis Middle Subscapular or Thoracodorsal N. Latissimus Dorsi Latissimus Dorsi Lower Subscapular N. Subscapularis Subscapularis Teres Major Teres Major

Brachial Plexus Branches & Muscular Innervations Median N. Abductor Pollicis Brevis/Longus Abductor Pollicis Brevis/Longus Flexor Carpi Radialis Flexor Carpi Radialis Flexor Digitorum Superficialis Flexor Digitorum Superficialis Flexor Digitorum Profundus (Lat. 2) Flexor Digitorum Profundus (Lat. 2) Flexor Pollicis Brevis (Lat.) & Longus Flexor Pollicis Brevis (Lat.) & Longus Lumbricales (Lat. 2) Lumbricales (Lat. 2) Opponens Pollicis Opponens Pollicis Palmaris Longus Palmaris Longus Pronator Quadratus Pronator Quadratus Pronator Teres * Pronator Teres * Radial N. Abductor Pollicis Brevis Abductor Pollicis Brevis Anconeus Anconeus Brachioradialis Brachioradialis Extensor Carpi Radialis Brevis/Longus Extensor Carpi Radialis Brevis/Longus Extensor Carpi Ulnaris Extensor Carpi Ulnaris Extensor Digiti Minimi Extensor Digiti Minimi Extensor Digitorum Communis Extensor Digitorum Communis Extensor Indicis Extensor Indicis Extensor Pollicis Brevis/Longus Extensor Pollicis Brevis/Longus Supinator Supinator Triceps Brachii Triceps Brachii

Brachial Plexus Branches & Muscular Innervations Ulnar N. Abductor Digiti Minimi Abductor Digiti Minimi Adductor Pollicis Adductor Pollicis Dorsal Interossei Dorsal Interossei Flexor Carpi Ulnaris Flexor Carpi Ulnaris Flexor Digiti Minimi Flexor Digiti Minimi Flexor Digitorum Profundus (Med. 2) Flexor Digitorum Profundus (Med. 2) Flexor Pollicis Brevis (Med.) Flexor Pollicis Brevis (Med.) Lumbricals (Med. 2) Lumbricals (Med. 2) Opponens Digiti Minimi Opponens Digiti Minimi Palmar Interossei Palmar Interossei Long Thoracic N. Serratus Anterior Serratus Anterior Medial Pectoral N. Pectoralis Major Pectoralis Major Medial Brachial Cutaneous N. (sensory) Medial Antebrachial Cutaneous N. (sensory)

Mechanisms of Injury to the Brachial Plexus

Brachial Plexus Injury Overview Sports most commonly associated with brachial plexus injuries include: football, baseball, basketball, volleyball, fencing, wrestling, and gymnastics Sports most commonly associated with brachial plexus injuries include: football, baseball, basketball, volleyball, fencing, wrestling, and gymnastics Nerve injuries can result from blunt force trauma, poor posture, or chronic repetitive stress Nerve injuries can result from blunt force trauma, poor posture, or chronic repetitive stress Patients generally present with pain and/or muscle weakness Patients generally present with pain and/or muscle weakness Over time, some patients may experience muscle atrophy Over time, some patients may experience muscle atrophy (Duralde, 2000)

Brachial Plexus Injury Overview Before performing special tests, rule out fractures and dislocations Before performing special tests, rule out fractures and dislocations Brachial plexus injuries resolve quicker than spinal cord injuries Brachial plexus injuries resolve quicker than spinal cord injuries (Prentice, p.846) Evaluation for return-to-play should take into consideration symptoms, resolution time, and prior injuries to this region Evaluation for return-to-play should take into consideration symptoms, resolution time, and prior injuries to this region (Gorden, et al., 2003) Evaluate athletes immediately after injury and again after the game/practice Evaluate athletes immediately after injury and again after the game/practice (Kuhlman & McKeag, 1998)

Three Mechanisms of Injury Percussion Percussion Traction Traction Cervical Nerve Compression Cervical Nerve Compression

Percussion Occurs with direct blow to the supraclavicular fossa over Erb’s point (Troub, 2001) Example: Cross-check to a hockey player

Traction Occurs with a direct blow to the shoulder with the neck laterally flexed toward the unaffected shoulder Occurs with a direct blow to the shoulder with the neck laterally flexed toward the unaffected shoulder (Troub, 2001) Example: Gymnast falls on beam

Cervical Nerve Compression Occurs when the neck is flexed laterally toward the patient’s affected shoulder Caused by compression or irritation of the nerves, resulting in point tenderness over involved vertebrae of affected nerve(s) (Troub, 2001) Example: Football player tackles an opponent

A. Traction B. Percussion C. Cervical Nerve Compression

Brachial Plexus Pathologies “Burners” or “Stingers” “Burners” or “Stingers” Associated with traction and/or compression Associated with traction and/or compression Thoracic Outlet Syndrome Thoracic Outlet Syndrome

Burners or Stingers Mechanisms of injury include cervical flexion away from the limb and hyperextension of the cervical spine Mechanisms of injury include cervical flexion away from the limb and hyperextension of the cervical spine May present with pain, numbness, burning, and/or tingling from the shoulder to the fingers May present with pain, numbness, burning, and/or tingling from the shoulder to the fingers Possible loss of function in arm and hand for several minutes up to several days Possible loss of function in arm and hand for several minutes up to several days (Prentice, p.846) (Prentice, p.846)

Thoracic Outlet Syndrome Caused by pressure on the brachial plexus and/or subclavian artery and/or vein Caused by pressure on the brachial plexus and/or subclavian artery and/or vein May present with numbness, paresthesia, pain, cool and pale skin, cyanosis or edema in upper extremity, and swollen veins May present with numbness, paresthesia, pain, cool and pale skin, cyanosis or edema in upper extremity, and swollen veins (Prentice, pp ) Patient may also develop unilateral atrophy and/or lowered shoulder on affected side Patient may also develop unilateral atrophy and/or lowered shoulder on affected side (Duralde, 2000)

Three Grades of Injury Grade 1 – Neuropraxia Grade 1 – Neuropraxia Grade 2 – Axonotmesis Grade 2 – Axonotmesis Grade 3 – Neurotmesis Grade 3 – Neurotmesis

Grade 1 - Neuropraxia Results in a disruption in the function of a nerve that produces numbness and tingling Results in a disruption in the function of a nerve that produces numbness and tingling Most common grade within athletics Most common grade within athletics Symptoms usually resolve within several minutes Symptoms usually resolve within several minutes(Duralde,2000)

Grade 2 - Axonotmesis Damage to the nerve’s axon Damage to the nerve’s axon Symptoms include numbness, tingling, and affected function (may last several days) Symptoms include numbness, tingling, and affected function (may last several days) Long nerves have a greater healing time than short nerves Long nerves have a greater healing time than short nerves Rare within athletics Rare within athletics (Duralde,2000) (Duralde,2000)

Grade 3 - Neurotmesis Permanent nerve damage occurs Permanent nerve damage occurs Very rare within athletics Very rare within athletics “Occurs with high-energy trauma, fractures, and penetrating injuries” “Occurs with high-energy trauma, fractures, and penetrating injuries” (Duralde, 2000)

C5-C6 Affected Motor Deficits: Motor Deficits: Shoulder abduction, shoulder flexion, elbow flexion, and wrist extension Sensory Loss: Sensory Loss: Lateral arm, 1 st digit, and 2 nd digit

C7 Affected Motor Deficits: Motor Deficits: Elbow extension weakness and wrist flexion Sensory Loss: Sensory Loss: Pad of index finger

C8-T1 Affected (very rare) Motor Deficits: Motor Deficits: Finger abduction/adduction and thumb flexors/extensors Sensory Loss: Sensory Loss: 4 th digit, 5 th digit, medial forearm, and medial arm

C5-T1 Affected Motor Deficits: Motor Deficits: Scapular motion and entire arm Sensory Loss: Sensory Loss: Entire arm, forearm, and hand

Process of Evaluation

Dermatomes C5 – Lateral arm C5 – Lateral arm C6 – Lateral forearm, thumb, index finger C6 – Lateral forearm, thumb, index finger C7 – Posterior forearm, middle finger C7 – Posterior forearm, middle finger C8 – Medial forearm, ring and little finger C8 – Medial forearm, ring and little finger T1 – Medial arm T1 – Medial arm

Myotomes C5 – Shoulder abduction C5 – Shoulder abduction C6 – Elbow flexion or wrist extension C6 – Elbow flexion or wrist extension C7 – Elbow extension or wrist flexion C7 – Elbow extension or wrist flexion C8 – Grip strength, shake hands C8 – Grip strength, shake hands T1 – Interossei, spread fingers and resist finger adduction T1 – Interossei, spread fingers and resist finger adduction

Peripheral Nerve Tests Musculocutaneous N. Sensory – Anterior armSensory – Anterior arm Motor – Elbow flexionMotor – Elbow flexion Axillary N. Sensory – Lateral armSensory – Lateral arm Motor – Shoulder abductionMotor – Shoulder abduction

Peripheral Nerve Tests Radial N. Sensory – 1 st Dorsal web spaceSensory – 1 st Dorsal web space Motor – Wrist extension and thumb extensionMotor – Wrist extension and thumb extension Median N. Sensory – Pad of Index fingerSensory – Pad of Index finger Motor – Thumb pinch and abductionMotor – Thumb pinch and abduction Ulnar N. Sensory – Pad of little fingerSensory – Pad of little finger Motor – Finger abductionMotor – Finger abduction

Reflex Tests C5 – Biceps brachii reflex (anterior arm near antecubital fossa) C5 – Biceps brachii reflex (anterior arm near antecubital fossa) C6 – Brachioradialis reflex (lateral aspect of forearm) C6 – Brachioradialis reflex (lateral aspect of forearm) C7 – Triceps brachii reflex (at insertion of tricep brachii) C7 – Triceps brachii reflex (at insertion of tricep brachii) C8 and T1 do not have reflex tests C8 and T1 do not have reflex tests

Related Special Tests Brachial Plexus Cervical Compression TestCervical Compression Test Cervical Distraction TestCervical Distraction Test Spurling’s TestSpurling’s Test Brachial Plexus Traction TestBrachial Plexus Traction Test Thoracic Outlet Syndrome Adson’s Test Adson’s Test Allen’s Test Allen’s Test Military Brace Position Military Brace Position

References Duralde, X. A. (2000). Neurologic injuries in athlete’s shoulder. Journal of Athletic Training, 35(3), pp Gorden, J. A., Straub, S. J., Swanik, C. B., & Swanik, K. A. (2003). Effects of football collars on cervical hyperextension and lateral flexion. Journal of Athletic Training, 38(3), pp Hoppenfeld, S. (1976). Physical Examination of the Spine & Extremities. Upper Saddle River: NJ: Prentice Hall. pp Kuhlman, G. S. & McKeag, D. B. (1999). The “burner”: A common nerve injury in contact sports. American Family Physician, 60(7). Retrieved April 5, 2006 from the American Academy of Family Physicians database. Martini, F. H., Timmons, M. J., & Tallitsch, R. B. (2003). Human Anatomy. Upper Saddle River, NJ: Pearson Education, Inc. Starkey, C. & Ryan, J. (2002). Evaluation of Orthopedic and Athletic Injuries. Philadelphia, PA: F. A. Davis Company. Troub, M. (2001). Brachial plexus injuries in athletics: “Burners”. Northwest Texas Sports Medicine Clinic. Retrieved March 5, 2006 from the Northwest Texas Sports Medicine Clinic website. Troub, M. (2001). Brachial plexus injuries in athletics: “Burners”. Northwest Texas Sports Medicine Clinic. Retrieved March 5, 2006 from the Northwest Texas Sports Medicine Clinic website.

Project Participants Presenters: Heather Terbeek, Hank House, Cesar Cardenas, and Rachel Sorris Presenters: Heather Terbeek, Hank House, Cesar Cardenas, and Rachel Sorris Models: Becky Roark & Kevin Geiger Models: Becky Roark & Kevin Geiger Researchers: Caitlin Wall, Heather Terbeek, Hank House, Cesar Cardenas, and Becky Roark Researchers: Caitlin Wall, Heather Terbeek, Hank House, Cesar Cardenas, and Becky Roark Special Thanks to Our Faculty: Jeff Roberts, Special Thanks to Our Faculty: Jeff Roberts, Dr. Leamor Kahanov, and Chris Warden