Cervical Strain

Acute injury to the cervical muscles and ligaments from sudden flexion, extension, rotation or lateral bending, including whiplash associated disorder from a rear end or side impact motor vehicle collision, sports injury, falls, and awkward sleeping or lifting.

• Whiplash associated disorder follows an acceleration deceleration mechanism. About 40 to 50% of patients are symptomatic after a collision, with most improving in weeks. About 20 to 40% have persistent pain at 3 to 6 months, and about 5 to 10% have severe long term disability.
• Risk factors for a poor outcome: high initial pain intensity (above 5 out of 10), high disability score, neck pain with radiating arm pain or neurological symptoms, older age, female sex, previous neck pain, low education, psychological distress (fear, anxiety, catastrophising), litigation or compensation processes, and a collision with unexpected impact.
• Severity grades for whiplash: grade 0 (no complaint), 1 (pain, stiffness or tenderness only), 2 (neck complaints with musculoskeletal signs, reduced movement and point tenderness), 3 (neck complaints with neurological signs), 4 (fracture or dislocation).

• Neck pain and stiffness, with onset within hours to 2 days of injury, often delayed rather than immediate. Associated symptoms: headache (usually occipital), shoulder and interscapular pain, dizziness, paraesthesia in the arms, fatigue, sleep disturbance, concentration difficulty, visual disturbance and jaw pain.
• Examination: muscle spasm, tenderness of paraspinal muscles and spinous processes, reduced range of movement (especially rotation and extension), and normal neurological findings in grade 1 and 2.
• Red flags needing imaging and urgent assessment: midline cervical bony tenderness, neurological deficit, age 65 or over, a dangerous mechanism (fall from above 1 metre or 5 stairs, axial load, high speed collision above 100 km/hour, rollover, ejection, bicycle collision), limb paraesthesia, inability to actively rotate the neck 45 degrees to each side, distracting injury, intoxication or reduced consciousness.
• Warning signs of vascular injury: severe neck pain with headache, Horner syndrome, dizziness, ataxia, diplopia, dysarthria, or focal weakness (carotid or vertebral artery dissection).
• Differential diagnosis: cervical fracture or ligamentous instability, disc herniation, facet joint injury, vertebral or carotid artery dissection, concussion, temporomandibular disorder, brachial plexus injury, shoulder injury, and spinal cord injury without radiographic abnormality.
• Complications: chronic whiplash associated disorder, cervicogenic headache, post-traumatic stress, depression, and chronic disability.

• Clinical assessment that starts with screening for fracture and instability: if the patient is high risk (age 65 or over, a dangerous mechanism, or limb paraesthesia), arrange imaging. If low risk (a simple rear end collision, sitting upright in the emergency department, ambulatory at any time, delayed onset of neck pain, and no midline tenderness), the patient may be assessed for active rotation of 45 degrees each way, and if able, no imaging is needed.
• CT of the cervical spine is the first line imaging for adults at risk. X-ray (anteroposterior, lateral, open mouth) is acceptable in younger patients with low probability injury. MRI for neurological deficit, ligament injury and disc herniation. CT or MR angiography when arterial dissection is suspected.
• Keep the spine protected with in line stabilisation until cleared in trauma.
• Screen for psychological distress and post-traumatic stress symptoms early.

• Early active management is better than rest:
  • Reassure the patient that most improve within weeks, and encourage early return to normal activity.
  • Avoid a soft collar beyond 24 to 72 hours, because prolonged collar use delays recovery. A collar is used only for short comfort in the first days.
  • Begin gentle, active range-of-movement exercises (rotation, flexion, extension, side bending) within a pain tolerable range, every 1 to 2 hours, from the first days.
• Analgesia:
  • Paracetamol 1 g orally 6 hourly (maximum 4 g per day).
  • NSAIDs for up to 1 to 2 weeks: ibuprofen 400 mg orally 8 hourly with food, naproxen 500 mg 12 hourly, or diclofenac 50 mg 8 hourly. Topical diclofenac 1% gel.
  • A short course (3 to 7 days) of a muscle relaxant for painful spasm: tizanidine 2 mg at night increasing to 2 to 4 mg 8 hourly, or cyclobenzaprine 5 to 10 mg at night, or diazepam 2 mg at night for 3 days, with a warning about drowsiness.
  • Codeine 30 mg with paracetamol for severe pain, for no more than 3 days.
  • Heat or ice, for 15 to 20 minutes several times a day, whichever the patient finds more comfortable.
• Physiotherapy for symptoms beyond 2 to 4 weeks: graded exercise (deep neck flexor and extensor training, scapular strengthening), postural advice, and manual therapy (mobilisation), 6 to 12 sessions. Work hardening and ergonomic adjustment.
• Persistent pain (over 3 months): multimodal rehabilitation with exercise and cognitive behavioural therapy, amitriptyline 10 to 25 mg at night or duloxetine 30 to 60 mg daily for sleep disturbance, neuropathic pain or depressive symptoms, and medial branch block with radiofrequency denervation for confirmed facet pain (about 50% of chronic whiplash pain is facet in origin). Treat post-traumatic stress and depression with psychological therapy.
• Vascular injury: treat dissection with antiplatelet therapy (aspirin 300 mg daily for 3 to 6 months) or anticoagulation (heparin then warfarin) under neurology or stroke teams.
• Fracture, dislocation or unstable ligament injury: immobilise and refer urgently to spinal surgery.
• Special groups:
  • Children: lower threshold for imaging with specialist radiation sparing protocols, and look for spinal cord injury without radiographic abnormality.
  • Pregnancy: paracetamol, heat, positioning, physiotherapy. Avoid NSAIDs after 20 weeks and muscle relaxants. Use ultrasound or MRI in preference to CT when possible, except when serious injury is suspected.
  • Elderly: higher fracture risk, avoid sedating relaxants and NSAIDs in renal impairment.
  • Anticoagulation: a low threshold for CT because of the risk of haematoma.
• Follow up: review at 1 to 2 weeks, then at 6 weeks. Refer to physiotherapy, spinal or pain services for persistent symptoms beyond 6 to 12 weeks, neurological signs, suspected instability, or severe psychological distress.