What causes neck pain radiating to the upper back or trapezius muscle?

Causes of Neck Pain Radiating to Upper Back/Trapezius

Neck pain radiating to the upper back and trapezius muscle is most commonly caused by mechanical cervical spine disorders—specifically cervical radiculopathy from nerve root compression, degenerative disc disease with facet joint arthropathy, and myofascial trigger points in the trapezius muscle itself. 1, 2

Primary Mechanical Causes

Cervical Radiculopathy

• Nerve root compression from herniated discs or osteophytes represents the primary neuropathic cause, typically presenting as neck pain with upper limb pain and varying degrees of sensory or motor deficits in the affected nerve root distribution 1, 2
• Compression occurs from soft disc herniation, hard disc (spondylarthrosis of facet or uncovertebral joints), or a combination of both 1
• The annual incidence is approximately 83 per 100,000 persons, making it a common cause of chronic neck pain 1
• 75-90% of cervical radiculopathy cases resolve with conservative nonoperative therapy 1

Degenerative Spine Disease

• Facet joint arthropathy causes localized mechanical pain that may be unilateral and radiate to the trapezius region 2
• Cervical spondylosis and degenerative disc disease are extremely common—53.9% of individuals aged 18-97 show disc degenerative changes, with prevalence increasing with age 1
• Critical pitfall: These degenerative changes correlate poorly with symptoms in isolation, as 85% of asymptomatic individuals over 30 years demonstrate spondylotic changes 2
• Uncovertebral joint hypertrophy and foraminal narrowing contribute to nerve irritation 1

Myofascial Pain Syndrome

• Myofascial trigger points (MTrPs) in the trapezius muscle are a direct cause of neck pain radiating to the upper back 3
• The intramuscular innervation zone (IZ) presents in an S-shaped belt in the middle of the trapezius muscle belly and is involved in chronic neck pain 3
• Impaired microcirculation in the trapezius muscle occurs in chronic trapezius myalgia, with consistently low local blood flow on the painful side 4
• Capsular ligament laxity causing cervical instability can lead to muscle spasms and chronic neck pain radiating to surrounding musculature 5

Serious Etiologies Requiring Urgent Evaluation

Red Flag Conditions

You must immediately investigate for these potentially life-threatening conditions:

• Vertebral osteomyelitis or discitis: Constitutional symptoms (fever, night sweats), elevated inflammatory markers (ESR, CRP, WBC), history of IV drug use or immunosuppression 2, 6
• Metastatic disease to cervical vertebrae: Intractable pain despite therapy, constitutional symptoms, vertebral body tenderness on palpation, history of malignancy 2
• Inflammatory arthritis: Persistent pain with elevated inflammatory markers 2
• Cervical myelopathy: Spinal cord compression presenting with progressive neurological deficits, gait disturbance, requires differentiation from radiculopathy through careful neurological examination 2
• Primary spinal tumors: Progressive symptoms refractory to conservative treatment 2

Critical Red Flags Checklist

Screen every patient for these indicators requiring immediate imaging 1, 2, 6:

• Constitutional symptoms (fever, unexplained weight loss, night sweats)
• Elevated inflammatory markers (ESR, CRP, WBC)
• History of malignancy or immunosuppression
• History of IV drug use
• Neurological deficits (weakness, sensory changes, gait disturbance)
• Intractable pain despite appropriate conservative therapy
• Vertebral body tenderness on palpation
• Trauma history

Diagnostic Approach Algorithm

Acute Neck Pain (<6 weeks)

• Do not order imaging in the absence of red flags, as most acute cervical neck pain resolves spontaneously or with conservative treatment 1, 2
• Approximately 50% of patients may have residual or recurrent pain up to 1 year after initial presentation 1
• Factors associated with poor prognosis include female gender, older age, coexisting psychosocial pathology, and radicular symptoms 1

Chronic Neck Pain (>12 weeks) or Radiculopathy

• If red flags are present: Obtain MRI cervical spine without contrast immediately 2, 6
• If no red flags but persistent symptoms beyond 6-8 weeks of conservative therapy: Consider MRI cervical spine without contrast 2
• MRI is the most sensitive imaging modality for detecting soft tissue abnormalities, disc herniation, nerve root impingement, inflammatory processes, infection, and tumor 1, 2

Physical Examination Considerations

• A positive Spurling's test is highly specific for nerve root compression from herniated cervical disc 2
• Document the specific dermatomal distribution of pain and any associated sensory or motor deficits to localize the affected nerve root level 2
• Critical limitation: Physical examination tests have limited evidence for accuracy in diagnosing cervical radiculopathy compared to imaging 1, 2
• MRI findings must always be interpreted in combination with clinical findings due to frequent false-positive and false-negative results 1

Imaging Pitfalls to Avoid

• Do not order imaging immediately in the absence of red flags—this leads to overdiagnosis of incidental degenerative changes that correlate poorly with symptoms 2
• Radiographs are widely accessible for initial screening of spondylosis, degenerative disc disease, and malalignment, but therapy is rarely altered by radiographic findings in the absence of red flags 1
• Do not interpret degenerative changes on imaging as causative without clinical correlation—a 10-year longitudinal MRI study showed 85% of patients with progression of cervical disc degeneration but only 34% developing symptoms 2
• CT offers superior bone detail but is less sensitive than MRI for nerve root compression, particularly from herniated discs 1

Treatment Implications Based on Etiology

Conservative Management

• Most cases (75-90%) of cervical radiculopathy resolve with conservative nonoperative therapy 1
• Lower trapezius strengthening exercises significantly reduce neck dysfunction, improve postural alignment, and increase muscle thickness and contraction rate 7
• Upper back manipulation can lessen pain and improve neck motion in patients with neck pain 8

Interventional Options for Myofascial Pain

• Lidocaine injection in the intramuscular innervation zone (IZ) of the trapezius is more effective than trigger point injection alone 3
• Combined lidocaine injection therapy in both the mid-upper trapezius (Point E) and lower trapezius (Point F) IZ locations provides superior pain reduction at 6 months compared to MTrP injection 3
• The IZ presents as an S-shaped belt in the middle of the trapezius muscle belly 3