• Epidemiology
  1. Uncommon to rare
  • Pathophysiology
  1. Scapular Winging results from innervation loss
    1. Long Thoracic Nerve (most common, C5-7 origin)
      1. Innervates serratus anterior Muscle
      2. Injured in strenuous Exercise or acute, forceful arm movement forward or backward
    2. Spinal Accessory nerve (Cranial Nerve 11)
      1. Innervates levator Scapulae and rhomboid Muscles
      2. Iatrogenic causes are most common (e.g. Lymph Node or Neck Mass excision)
    3. Dorsal Scapular Nerve (C4-5 origin)
      1. Innervates trapezius Muscle
      2. Injury occurs with strenuous activity or lifting
  2. Results in paralysis of the trapezius Muscle, rhomboid Muscles, or serratus anterior Muscle
    1. Allows the Scapula to separate from the underlying thoracic wall with Shoulder movement
  • Signs
  1. Serratus anterior weakness (Long Thoracic Nerve Palsy)
    1. Medial Scapula Winging increased when arms forward flexed and pushing against the wall
    2. Overhead abduction reduced (last 30 degrees lost)
  2. Levator Scapulae and rhomboid Muscle Weakness (Cranial Nerve 11 palsy)
    1. Lateral Scapula Winging increased when arms abducted
  3. Trapezius Muscle Weakness (Dorsal Scapular Nerve Palsy)
    1. Lateral Scapula Winging increased when arms abducted (similar to Cranial Nerve 11 palsy)
    2. Shoulder Abduction above 90 degrees is difficult
    3. Affected Shoulder droops
  • Imaging
  1. Evaluate for alternative causes
    1. Shoulder XRay
    2. Cervical Spine XRay
  • Diagnostics
  1. Consider Electromyogram
  • Differential Diagnosis
  1. See Cervical Spine Injury
  2. See Shoulder Injury
  • Management
  1. Oral Analgesics as needed (e.g. NSAIDS)
  2. Relative rest of affected Shoulder
  3. Physical Therapy
  • Prognosis
  1. Most patients recover within 2 years with physical therapy and without surgery
  • References
  1. Kuczynski (2023) Crit Dec Emerg Med 37(10): 12-3
  2. Didesch (2019) J Hand Surg Am 44(4):321-30 +PMID: 30292717 [PubMed]
  3. Gooding (2014) Shoulder Elbow 6(1):4-11 +PMID: 27582902 [PubMed]