Muscle:Semispinalis Cervicis

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Semispinalis cervicis is an intermediate-to-deep posterior cervical muscle whose trigger points (TrPs) refer pain into the occipital region in a pattern similar to that of the middle semispinalis capitis, and downward over the neck to the upper vertebral border of the scapula. It is primarily a cervical extensor and contralateral rotator, and its caudal attachments to the relatively immobile thoracic vertebrae serve primarily as anchors for movement of the cervical spine.

Because it lies deep to the semispinalis capitis and its digitations are diagonally oriented, it requires deeper palpation — approximately 1–2 cm lateral to the spinous processes — to access its TrPs. Its involvement is frequently part of a multi-muscle posterior cervical TrP complex.

Contents

Anatomy

The semispinalis cervicis lies deep to the semispinalis capitis. It attaches below to the transverse processes of the first to fifth or sixth thoracic vertebrae. Above, it attaches to the spinous processes of the second to fifth cervical vertebrae. Toward its cephalic end, it becomes thicker and more muscular. The fibres of the semispinalis cervicis usually span 5 vertebrae. The diagonal orientation of its digitations can be seen in the cross-sectional view at Figure 48.4 of the source volume.

It is intermediate between the semispinalis capitis and multifidi in depth, fibre length, and angulation of fibres. It belongs to the third anatomical layer of the posterior cervical muscles (along with the semispinalis capitis), while the multifidi and rotatores constitute the fourth and deepest layer.

Primary actions: Extension of the cervical vertebral column; rotation of the cervical spine to the opposite side. The caudal attachments to the relatively immobile thoracic vertebrae serve primarily as anchors for movement of the cervical spine.

This muscle also provides a checkrein function during even slight flexion of the neck, analogous to the semispinalis capitis for the head.

Innervation: Third to sixth cervical spinal nerves.

Main synergists (extension): Splenius cervicis bilaterally, longissimus cervicis, semispinalis capitis, levator scapulae bilaterally, plus the multifidi acting bilaterally.

Synergists (neck rotation): Contralateral splenius cervicis and levator scapulae; ipsilateral multifidi and rotatores.

Antagonists: Anterior neck muscles, including the strap muscles and longus colli.

Referred Pain Patterns

The TrP location and the pain pattern are not illustrated separately for this muscle in the source volume. It is likely to refer pain into the occipital region in a pattern similar to that shown for the middle semispinalis capitis (Location 3 pattern), and downward over the neck to the upper vertebral border of the scapula.

The C₂–C₃ zygapophysial joint refers pain in patterns that overlap part of the pain distribution of semispinalis cervicis TrPs and must be considered in the differential diagnosis.

Activation and Perpetuating Factors

  • Sustained forward head posture with the neck in flexion — checkrein overload is the dominant chronic mechanism, identical to semispinalis capitis
  • Motor vehicle accident (whiplash): the semispinalis cervicis, multifidi, and rotatores muscle groups can form articular dysfunctions at various levels of the cervical and upper thoracic spine depending on specific attachments; whiplash activates TrPs throughout the posterior cervical complex
  • Prolonged reading or writing at a flat surface, operating a computer terminal, or sewing
  • Lying supine without a pillow or with a too-hard, poorly-fitted pillow (excessive cervical extension at night)
  • Emotional depression
  • Neuropathy: increased nerve irritability from spinal radiculopathy can be a significant factor in activation and perpetuation of posterior cervical TrPs
  • Facet joint arthritis: C₃–C₄ and C₄–C₅ zygapophysial joints are particularly associated with semispinalis cervicis TrPs

Clinical Examination

One palpates for TrP tenderness of this intermediate-to-deep posterior cervical muscle 1–2 cm lateral to the spinous processes.

A common TrP location is at approximately the C₄–C₅ level. Deep pressure on the TrP may elicit referred pain over the occipital region, similar to the pattern shown for the middle semispinalis capitis (Fig. 16.1C of the source volume).

The digitations of this muscle are deep to the semispinalis capitis (see cross-sectional view at Fig. 16.8). The diagonal orientation of each digitation can be seen in Figure 48.4. Only rarely can one distinguish taut bands in this relatively deep muscle.

Slight flexion of the head and neck enhances taut band tension and makes TrPs more distinguishable by palpation if the posterior cervical musculature has been relaxed by providing adequate head and body support.

Articular screen: The semispinalis cervicis, multifidi, and rotatores groups can form articular dysfunctions at various levels. Extension dysfunctions of T₁–T₄ segments are an important articular dysfunction associated with TrP involvement of bilateral posterior cervical muscles that attach to or span the upper thoracic vertebrae — particularly the semispinalis cervicis, multifidi, and rotatores. Treat these extension dysfunctions from T₁ to T₄ using a manual stretch technique that incorporates contract-relax and forward flexion progressing down the spine segment by segment.

Differential Diagnosis

Condition Distinguishing features
Semispinalis capitis TrPs Semispinalis capitis lies superficial to semispinalis cervicis; semispinalis capitis refers in a band to the temporal region and over the eye; semispinalis cervicis refers to the occiput and toward the scapular border; both may coexist and palpation depth distinguishes them
C₂–C₃ zygapophysial joint pain Overlapping pain patterns; both must be evaluated and treated; cervical joint pain provoked by passive motion assessment and joint palpation; myofascial TrP pain reproduced by muscle palpation; frequently coexist
Cervical multifidi TrPs Multifidi lie deeper than semispinalis cervicis; multifidi TrP palpation is approximately halfway between a spinous process and a lower transverse process; articular dysfunctions at the same level commonly coexist with multifidi TrPs
Cervical radiculopathy C₄–C₈ Radiculopathy from C₄–C₆ rarely fails to cause limb signs or symptoms; positive Spurling test; electrodiagnostic findings helpful; TrPs and radiculopathy can coexist — each must be diagnosed on its own criteria

Treatment

Trigger Point Release

Released as part of the diagonal posterior cervical muscle group using a flexion-and-rotation stretch:

Diagonal posterior cervical muscles — spray and stretch (Fig. 16.7):

  1. To stretch the right "∧" diagonal muscles (semispinalis cervicis, multifidi, rotatores), and the left "∨" diagonal muscles (splenius): patient gently flexes the neck and rotates the face to the left (opposite side from the right ∧ muscles being stretched), with manual monitoring by the clinician
  2. Vapocoolant is applied bilaterally in a diagonal upsweep pattern that follows the line of the stretched fibres on both sides of the neck, since stretch of the "∨" diagonal muscles on the right also stretches the "∧" diagonal muscles on the left
  3. Manual release of diagonal muscles (Fig. 16.7C): patient supine, examiner's hand cradles the head while the other hand stabilises at the level of the shoulder; direction of movement with traction is toward the left with neck flexion and left rotation; particularly effective for the right "∨" diagonal muscles (e.g., splenius)
  4. The corresponding procedure is done toward the opposite side with a change of hand position for the remaining diagonal muscles

Spray and stretch alone with unidirectional parallel sweeps usually releases that movement only partially. Adjacent tight restricting muscle fibres must also be released.

Trigger Point Injection

TrPs in the semispinalis cervicis are deep to the semispinalis capitis. TrPs are not likely to be found above the level of the C₄ spinous process. A common TrP location is at approximately the C₄–C₅ level.

The needle must penetrate several layers of muscle (the semispinalis capitis and cervicis, after first passing through the trapezius and splenius capitis muscles). The TrP is usually encountered at least 2 cm (¾ in) deep to the skin, and may lie beyond the reach of a 3.8-cm (1½-in) needle — a 5-cm (2-in) needle may be needed (Fig. 16.8).

Penetration into the spinal canal is avoided by always angling the needle slightly laterally when injecting the deeper paraspinal muscles. In some patients, the cervical spinal cord may not be covered by bone between vertebrae as far as 1 cm or more lateral to the edge of a cervical spinous process — depth of the lamina at 2 cm lateral to the lateral edge of a cervical spinous process should be established, and the needle should not be inserted to a greater depth whenever it is directed more medially.

Injection of posterior cervical muscles is frequently bilateral. Injection is followed immediately by spray and stretch and full active range of motion.

Corrective Actions

Same as for Semispinalis Capitis — Corrective Actions. The combined shower self-stretch exercise (Fig. 16.11) is a primary self-therapy tool.

Satellite Trigger Points

References

  • Travell JG, Simons DG. Myofascial Pain and Dysfunction: The Trigger Point Manual, Volume 1: The Upper Half of Body. 2nd ed. Baltimore: Williams & Wilkins; 1999. Chapter 16.
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