Suprascapular Nerve Palsy

Ovid: 5-Minute Sports Medicine Consult, The

Suprascapular Nerve Palsy
Philip H. Cohen
James C. Puffer
  • Relatively uncommon; true incidence unknown
  • May occur in up to 45% of international-level volleyball players
  • Ganglion cyst found at spinoglenoid notch in 1% of cadavers in one study
  • Spinoglenoid ligament present in 50–60% of shoulders
  • Suprascapular neuropathy in 7% of athletes with peripheral nerve injuries
Risk Factors
  • More common in volleyball players and overhead throwing athletes, possibly owing to traction injury or scar formation from overuse
  • May be particularly associated with “floating serve” in volleyball, which requires intense eccentric contraction of infraspinatus to decelerate the arm and stabilize the shoulder; this can stretch the suprascapular nerve across the lateral edges of the scapular spine.
  • Sudden downward depression of shoulder (traction injury to nerve near plexus origin)
  • Compression by ganglion cyst, tumor, posttraumatic calcification, vascular malformation, or ligament at scapular or spinoglenoid notch
  • Direct trauma, eg, scapular fracture
  • Suprascapular nerve arises from the upper trunk of the brachial plexus at Erb's point, carrying fibers from the C5 and C6 nerve roots with variable contributions from C4.
  • It crosses the posterior triangle of the neck, runs deep to the trapezius, and passes under the transverse scapular ligament via the scapular notch.
  • Crossing the supraspinatus fossa, it sends 2 branches to the supraspinatus and sensory branches to the acromioclavicular and glenohumeral joints.
  • The nerve makes a sharp turn around the spinoglenoid notch and passes into the infraspinatus fossa, where its branches terminate.
  • 3 main sites of injury:
    • Scapular notch
    • Spinoglenoid notch
    • Near the origin from the upper trunk of brachial plexus
  • Traumatic versus atraumatic? May yield clues to mechanism of injury; traction injury caused by blunt trauma has a good prognosis.
  • Painful versus painless? Painless weakness suggests distal lesion.
  • Overhead-throwing athlete? If yes, this may increase risk of suprascapular nerve lesion.
Physical Exam
  • Signs and symptoms depend on level of injury.
  • If proximal, may have posterior/lateral shoulder pain along with weakness and atrophy of supraspinatus and infraspinatus
  • If lesion is distal to sensory branches at spinoglenoid notch, painless, isolated infraspinatus atrophy and weakness of external rotation may be seen.
  • Inspection is key. Look for supraspinatus or (especially) infraspinatus atrophy.
  • Rule out cervical radiculopathy and other C-spine pathology (complete neck exam, including the Spurling maneuver)
  • External rotation testing against resistance to evaluate infraspinatus strength
  • Jobe test to evaluate supraspinatus strength
  • Complete neurologic examination to determine type, origin, and extent of injury; note that deep tendon reflexes should not be affected in isolated suprascapular neuropathy.
  • Thorough shoulder examination to evaluate for associated injury
  • Tenderness to palpation at scapular notch present in up to 77% patients
  • Cross-body adduction test (forward flexed arm externally rotated and adducted across body) puts tension on suprascapular nerve at spinoglenoid notch; may help to differentiate from rotator cuff lesion
  • Injection into scapular notch may help to determine source of pain but is rarely necessary.


Diagnostic Tests & Interpretation
  • Plain films of the neck and shoulder evaluate for bony abnormalities.
  • 30-degree cephalic tilt view helps to visualize the scapular notch; obtain especially if scapular fracture.
  • MRI may be used to detect ganglion cysts and tumors affecting the suprascapular nerve, as well as other shoulder pathology (rotator cuff injury, labral tears, etc.).
  • US can be similarly useful in detecting lesions affecting the suprascapular nerve; it also can be quickly used to evaluate the rest of the shoulder girdle during the same exam. However, it is extremely operator-dependent.
Diagnostic Procedures/Surgery
  • Electromyography of entire shoulder girdle
  • Nerve conduction velocity studies from Erb's point to the supraspinatus, with comparison to unaffected side
  • Wait minimum 3–4 wks after onset of complaint before neurodiagnostics because false-negative results may occur if done earlier.
Differential Diagnosis
  • Cervical radiculopathy
  • Brachial plexopathy/“stinger”
  • Rotator cuff tendonitis/tear
  • Labral pathology
  • Turner-Parsonage syndrome/neuritis
Ongoing Care
354.8 Other mononeuritis of upper limb

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