Posterolateral Neck Flexors Strength Test

The Posterolateral Neck Flexors Strength Test is a manual muscle test used to assess the strength of the posterolateral neck muscles—primarily including the splenius capitis and cervicis, semispinalis capitis and cervicis, and the cervical erector spinae on one side. This group of muscles is key for neck extension, rotation, and lateral flexion, supporting head posture and functional movement.

How the Test is Performed

• Client position: Supine (lying on back)

• The client abducts both arms to 90°, elbows flexed to 90°, and the dorsal hands resting on the table.

• The client extends the neck and then rotates the head towards the side being tested.

• The therapist stabilizes the side being tested for support.

• The client is asked to hold the head in this posterolaterally extended/rotated position against gravity (for a grade 3 muscle test).

• To further challenge strength (grade 4–5), the therapist applies resistance against the temporalis area of the head on the unaffected side, pressing in an oblique posterolateral direction away from the tested side.

• Positive for weakness: The client is unable to hold their head in the position against gravity or therapist resistance.

Clinical Significance

• Weakness in these muscles may reflect postural imbalance, previous injury, cervical muscle strain, chronic pain, or neurological impairment.

• The posterolateral neck flexors play a crucial role in maintaining head and neck alignment against gravity and during functional rotation/lateral flexion.

Assessment

• Use this test for clients presenting with:

  • Neck pain, cervical dysfunction, headaches, poor posture

  • History of whiplash or cervical strain injuries

• Document:

  • The ability to maintain the test position with and without resistance

  • Any observable compensation, trembling, or pain during testing

  • Left-right asymmetry or rapid onset of fatigue

Treatment

• If weakness is found:

  • Incorporate isometric and graded strengthening exercises for the cervical extensors and rotators into the treatment plan.

  • Pair strengthening with soft tissue techniques to address overused/compensating areas and correct posture.

  • Educate clients on cervical posture, ergonomics, and movement patterns to reduce future strain.

• Gradually increase load and complexity as tolerance and strength improve.

Safety and Referral

• If profound weakness, rapid decline, or any neurological symptoms are noted, refer to a physician or physiotherapist for further evaluation.

• Always be cautious and avoid forceful resistance in the presence of acute pain, trauma, or suspected instability.