Splenius Cervicis: Origin, Insertion, Nerve, Action & Neck Pain

The Splenius Cervicis is the lower, narrower partner to the Splenius Capitis. While the Capitis attaches to the skull, the Cervicis ("of the neck") attaches to the cervical vertebrae. It connects the upper thoracic spine to the upper cervical spine, acting as a critical extender and rotator of the neck.

[Image of Longissimus Cervicis anatomy]

Quick Anatomy Snapshot

Layer	Superficial layer of intrinsic back muscles (Spinotransversales).
Origin (Proximal)	Spinous Processes of T3 to T6.
Insertion (Distal)	Posterior tubercles of the Transverse Processes of C1 to C3.
Nerve Supply	Lateral branches of the Posterior Rami of lower cervical spinal nerves.
Primary Actions	Bilateral: Extension of the neck. Unilateral: Lateral flexion and Rotation of the neck to the same side (Ipsilateral).

Deep Dive: The Neck Link

The Splenius Cervicis is often overshadowed by the Capitis, but its attachment to the Atlas (C1) gives it significant influence over upper cervical mechanics.

1. The Lateral Position

As the muscle travels superiorly, it diverges laterally. It starts at the midline (Thoracic Spinous Processes) and travels up and out to the side of the neck (Cervical Transverse Processes). This diagonal path gives it excellent leverage for rotation.

2. Relationship to Levator Scapulae

At its insertion on the transverse processes of C1-C3, the Splenius Cervicis lies immediately deep to the Levator Scapulae. This area is a common "hotspot" for knots, as multiple muscles compete for attachment space on these small bony tubercles.

Physio Corner: Clinical Relevance

💪 Functional Fact: The Splenius Cervicis works with the contralateral Sternocleidomastoid (SCM) and Upper Trapezius to rotate the head. While the SCM rotates to the opposite side, the Splenius Cervicis rotates to the same side.

Palpation

1. Locate the spinous processes of T3-T6.
2. Follow the muscle fibers upwards and outwards toward the side of the neck.
3. The insertion is deep to the Levator Scapulae and SCM on the side of the neck.
4. Palpation is best done in the triangle between the Trapezius and SCM, just below the mastoid process (deep layer).

⚠️ Clinical Pathology: Referred Pain
Trigger points in the Splenius Cervicis are famous for referring pain "through the head" to the back of the eye (retro-orbital pain) and causing blurred vision. This is distinct from Splenius Capitis, which refers pain to the top of the head.

Manual Muscle Testing (MMT)

Tested alongside Splenius Capitis as a general neck extensor/rotator.

Testing Tip: Focus on neck extension rather than head extension (chin lift). The Splenius Cervicis acts on the cervical spine, not the atlanto-occipital joint.

Step-by-Step Procedure (Oxford Scale)

Grade	Patient Action & Resistance
Grade 3, 4, 5 (Against Gravity)	Position: Prone. Neck flexed slightly. Action: Patient extends the neck and rotates to the Same Side. Resistance: Applied to the posterolateral head, pushing down into flexion and opposite rotation. Grade 3: Active ROM against gravity. Grade 4/5: Holds against resistance.
Grade 0, 1 (Palpation)	Action: Palpate lateral to the cervical spinous processes, deep to the Trapezius. Cue: "Try to turn your head and look back."

Frequently Asked Questions

What is the main difference between Splenius Capitis and Cervicis?

Capitis: Originates Ligamentum Nuchae/C7-T3, Inserts on Skull. Moves the Head.
Cervicis: Originates T3-T6, Inserts on C1-C3 Vertebrae. Moves the Neck.

Does it attach to the skull?

No. It stops at the Atlas (C1) vertebra. Only the Splenius Capitis attaches to the skull (Mastoid/Occiput).

Does it help with posture?

Yes. It is an important anti-gravity muscle that prevents the neck from dropping forward into flexion (Kyphosis). It is often strained in "Text Neck" posture.

Test Your Knowledge: Splenius Cervicis Quiz

1. Where does Splenius Cervicis insert?

2. What is the unilateral action of Splenius Cervicis?

3. Which muscle lies superficial to the Splenius Cervicis?

4. Splenius Cervicis trigger points commonly refer pain to:

5. Where does the Splenius Cervicis originate?

6. Which nerve supplies this muscle?

7. Which muscle shares the insertion on the C1-C3 transverse processes?

8. The Splenius Cervicis runs in which direction from origin to insertion?

9. Is Splenius Cervicis part of the Erector Spinae?

10. True or False: Splenius Cervicis assists in breathing.

References

• Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2018). Clinically Oriented Anatomy. 8th ed. Philadelphia: Wolters Kluwer.
• Standring, S. (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice. 41st ed. Elsevier.
• Travell, J. G., & Simons, D. G. (1999). Myofascial Pain and Dysfunction: The Trigger Point Manual. 2nd ed. Williams & Wilkins.