Splenius Cervicis
Back · Trunk
The splenius cervicis is a strap-like muscle of the superficial layer of the deep back, lying beneath the trapezius and deep to the serratus posterior superior. It arises from the spinous processes of the third to sixth thoracic vertebrae and ascends laterally to insert onto the posterior tubercles of the transverse processes of the upper cervical vertebrae, C1 to C3. Because its fibres run upward and laterally, acting bilaterally it extends the neck, while acting on one side it rotates and laterally flexes the head and neck toward that same side, working in concert with the splenius capitis above it. It is innervated by the posterior (dorsal) rami of the lower cervical spinal nerves.
Origin, Insertion, Action & Nerve
Origin
Spinous processes of T3–T6
Insertion
Posterior tubercles of the transverse processes of C1–C3
Action
Bilaterally extends the neck; unilaterally rotates and laterally flexes the head and neck to the same side
Nerve
Posterior (dorsal) rami of lower cervical spinal nerves
Attachments explained
The Splenius Cervicis is defined first by where it attaches. Its origin is the more fixed anchor, usually the proximal or more stable end that stays put during contraction, while its insertion is the more mobile point that is pulled toward the origin when the muscle shortens.
Origin
Spinous processes of T3–T6
Insertion
Posterior tubercles of the transverse processes of C1–C3
Action & function
When the Splenius Cervicis contracts, it produces the following movements: Bilaterally extends the neck; unilaterally rotates and laterally flexes the head and neck to the same side.
As part of the Back group of the Trunk, it works alongside neighbouring muscles to generate smooth, coordinated movement and to stabilise the structures it acts on.
Nerve supply & clinical relevance
The Splenius Cervicis receives its nerve supply from the Posterior (dorsal) rami of lower cervical spinal nerves.
Because a muscle can only contract when its nerve is intact, injury to the Posterior can weaken or paralyse the Splenius Cervicis, impairing the movements it normally produces (bilaterally extends the neck). This is why knowing the innervation is central to localising nerve lesions in clinical practice.
How to study the Splenius Cervicis (the OIANS method)
Learn splenius cervicis as the lower partner of splenius capitis, the two together forming a bandage-like layer, which is exactly what splenius means. Note the crossing arrangement: it starts on thoracic spinous processes in the midline and travels up and out to reach cervical transverse processes, so its diagonal pull naturally produces ipsilateral rotation and lateral flexion, with bilateral action giving pure extension.
Contrast its insertion with that of splenius capitis to keep the pair distinct: capitis reaches the skull at the mastoid process and nuchal line, whereas cervicis stops at the transverse processes of C1 to C3. Both belong to the deep back and are therefore supplied by posterior (dorsal) rami, so once you know one nerve rule you know both.
Frequently asked questions
Where is the Splenius Cervicis located?
The Splenius Cervicis is a muscle of the Back group, located in the Trunk.
What is the origin of the Splenius Cervicis?
Spinous processes of T3–T6
What is the insertion of the Splenius Cervicis?
Posterior tubercles of the transverse processes of C1–C3
What movements does the Splenius Cervicis produce?
Bilaterally extends the neck; unilaterally rotates and laterally flexes the head and neck to the same side
What nerve supplies the Splenius Cervicis?
Posterior (dorsal) rami of lower cervical spinal nerves
Is the Splenius Cervicis free to study in OIANS?
The Splenius Cervicis is always free to browse. Its full origin, insertion, action and nerve details are open to everyone in the Muscle Directory. Quiz and Flashcard practice for the Trunk is part of the one-time Lifetime upgrade, though; only the Upper Limb decks are free to test yourself on.
Related muscles
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