Muscle:Rotatores

Rotatores are the deepest layer of the deep paraspinal (transversospinal) group and the shortest muscles of the spine. They span only one segment (rotatores breves) or two segments (rotatores longi) and lie against the laminae of the vertebrae. Their trigger points (TrPs) produce midline pain centred on the spinous processes at the segmental level of the TrP, with referred tenderness that may extend to the adjacent tapping on the spinous process. They are the most precise segmental stabilisers of the spine, acting as dynamic ligaments that adjust small movements between individual vertebrae.

Involvement of the rotatores throughout the length of the thoracolumbar spine produces midline pain and referred tenderness on tapping on the spinous process adjacent to a TrP. Only deep palpation of the muscles can determine from which side the midline pain arises. This tenderness is used as an osteopathic sign of articular-dysfunction involvement of that vertebra.

Anatomy

The rotatores are the deepest layer of the transversospinal group, lying between the multifidi (which lie superficial to them) and the vertebral laminae. They occupy the groove between the spinous and transverse processes.

• Rotatores breves — short rotatores; attach to adjacent vertebrae (span one segment)
• Rotatores longi — long rotatores; span one segment throughout the thoracic and lumbar spine

The rotatores occur above the sacral level. Only the multifidi extend across sacral segments. The deeper multifidi and rotatores muscles attach medially and above near the base of a vertebral spinous process. Laterally and below they attach to a transverse process.

The fibres of the progressively deeper muscles of the deep group also become progressively shorter and more horizontal, increasingly rotating the spine rather than primarily extending it.

Primary function: The deepest transversospinal (rotatores) muscles act as dynamic ligaments that adjust small movements between individual vertebrae — fine adjustments rather than gross spinal movements. Acting bilaterally with the other deep paraspinal muscles, they contribute to extension of the vertebral column. Acting unilaterally, they rotate the vertebrae to the contralateral side.

Innervation: Medial branches of the dorsal primary divisions of the spinal nerves. In the lower thoracic and lumbar regions, the nerve, the rotator muscle, and the tip of the spinous process which has the same number as the nerve, are at the same level.

Referred Pain Patterns

Involvement of the rotatores produces midline pain centred on the spinous processes at the segmental level of the TrP (Fig. 48.2A). Referred tenderness on tapping the adjacent spinous process is characteristic. This midline tenderness is easily located by tapping each spinous process in succession; it disappears after inactivation of the responsible TrPs, which may be located on either or both sides of the spine.

TrPs in the rotatores can induce a concurrent single-level articular dysfunction, in contrast to the multifidi (which more likely induce dysfunction involving two or three adjacent segmental levels) and the semispinalis (which is associated with four to six segmental levels of dysfunction).

The severe aching "bone" pain from TrPs in any of the deep group of paraspinal muscles is persistent, worrisome, and disabling.

Activation and Perpetuating Factors

• Sudden overload: A quick awkward movement combining bending and twisting of the back, especially when muscles are fatigued or chilled
• Sustained overload: Sustained contraction in the stooped posture, or in a fully shortened (hyperlordotic) position
• Structural asymmetries: Lower limb-length inequality, pelvic asymmetry — these perpetuate TrPs and must be corrected
• Articular dysfunction: TrPs in the rotatores can induce a concurrent single-level articular dysfunction; conversely, articular dysfunction can perpetuate rotator TrPs
• Deep thoracic kyphosis: Deep thoracic paraspinal TrPs, including the rotatores, tend to occur in patients with marked thoracic kyphosis
• Prolonged immobility: Sitting for hours in aircraft or automobile with seat belt fastened

Clinical Examination

Deep Paraspinal Examination

Active TrPs in the deep paraspinal muscles cause guarded movements and restrict side bending, rotation, and hyperextension of the trunk.

During flexion, a hollow or flat area develops in the smooth curve formed by the spinous processes; the flattening usually spans one to three vertebrae. Involvement of a rotator muscle on either side produces midline tenderness over the adjacent spinous process.

Examination technique:

1. Patient is recumbent or seated and leaning forward to flex the spine
2. The examiner taps or presses on the tips of successive spinous processes to elicit tenderness
3. When a spinous process in the flat area is hypersensitive, the deep musculature on each side of it is palpated by firm pressure in the groove between the process and the longissimus muscle
4. Deep finger pressure is directed along the side of the spinous process to exert pressure on the rotatores against the underlying laminae, to locate a spot of maximum tenderness
5. If two or three spinous processes are tender, one expects to find adjacent TrPs on at least one side at each level of tenderness

The apex segment is often exquisitely tender to palpation. Single-level tenderness points toward rotator involvement; multi-level tenderness (four to six segments) points toward semispinalis involvement; two to three adjacent segments points toward multifidus involvement.

Differential Diagnosis

Condition	Distinguishing features
TrPs in the rotatores can induce a concurrent single-level articular dysfunction; this is best treated by inactivating the TrPs, by rib-mobilising muscle stretch using respiration to augment relaxation, or by functional (indirect) techniques
Lumbar facet (zygapophysial) syndrome	Referred pain characteristic of lumbar zygapophysial joints overlaps pain referred from the deep paraspinal muscles; manual release techniques for articular dysfunctions are as effective for releasing the tense deep spinal muscles
Visceral disease	Rotator TrP pain is midline and may be mistaken for visceral referral; identify by segmental palpation and spinous process tapping
Radiculopathy	When radiculopathy activates TrPs, they may persist long after nerve root compression has been relieved; these TrPs produce stiffness and pain similar to radicular pain and may contribute to failed-back syndrome
Osteoarthritis	Radiographic signs of degenerative joint disease correlate poorly with the occurrence of pain; many patients with spinal abnormalities are completely relieved when the responsible TrPs are inactivated

Treatment

Trigger Point Release — Deep Paraspinal Muscles

To stretch the multifidus and rotatores muscles, the seated patient's spine is flexed and simultaneously rotated, turning the chest toward the side of the involved muscle (Fig. 48.7):

1. After initial sweeps of vapocoolant spray, the operator takes up the slack and repeats the process several times to achieve full normal range of motion
2. To incorporate PIR, the patient looks first toward the contralateral side while the examiner resists any attempt to turn the torso; then the patient relaxes and turns toward the involved side
3. Release of the tense deep paraspinal muscles is augmented through reciprocal inhibition if the patient gently voluntarily assists rotation toward the involved side

Many manual release techniques directed toward spinal articular dysfunctions are as effective for releasing the tense deep spinal muscles as they are for releasing restricted joint movement.

Trigger Point Injection — Deep Paraspinal Muscles

The TrPs in the deep paraspinal thoracic muscles are injected by directing the needle caudally (not upward) and slightly medially. For the rotatores, which lie against the laminae of the vertebrae and attach at the base of each spinous process, a needle at least 5 cm (2 in) long is used. It is directed somewhat caudally and medially, nearly parallel to the long axis of the spine and toward the base of the spinous process, but not between the spinous processes.

This needle angle eliminates the possibility of introducing the needle between the ribs into the pleural cavity, or between the vertebrae into the epidural space. The caudal slant is indicated because of the shingle-like overlap of the laminae. Penetration to a depth greater than the laminae is unnecessary and undesirable.

Corrective Actions

See Longissimus Thoracis — Corrective Actions for the full programme. For the deep paraspinal group specifically:

• Passive stretch exercises for the paraspinal muscles
• Graded active strengthening exercises for the abdominal muscles
• Correction of structural inadequacies (leg-length discrepancy, small hemipelvis)

Satellite Trigger Points

• Multifidus — overlying layer; co-active; multifidus TrPs are more likely to induce two to three segmental levels of dysfunction
• Semispinalis Thoracis — outermost of the deep group; co-active at thoracic levels
• Longissimus Thoracis — superficial group; frequently co-involved

Related Pages

• Muscle:Multifidus — overlying layer of the deep paraspinal group
• Muscle:Semispinalis_Thoracis — outermost of the deep paraspinal group
• Muscle:Longissimus_Thoracis — superficial group; frequently co-involved
• Muscle:Iliocostalis_Thoracis — superficial group; frequently co-involved
• Pain:Low_Back — diagnostic algorithm for back pain

References

• Travell JG, Simons DG. Myofascial Pain and Dysfunction: The Trigger Point Manual, Volume 2: The Lower Extremities. Baltimore: Williams & Wilkins; 1992. Chapter 48.