The Erector Spinae Group

The nine (9) muscles of the Erector spinae group are deep back muscles. They include the Iliocostalis Lumborum, Iliocostalis Thoracis, Iliocostalis Cervicis, Longissimus Thoracis, Longissimus Cervicis, Longissimus Capitis, Spinalis Thoracis, Spinalis Cervicis, and Spinalis Capitis.

Longissimus Thoracis

The Longissimus Thoracis is a deep muscle of the back.

Anatomical Attachments:

• Origin: Attaches to the transverse processes of the lumbar vertebrae and the lumbodorsal fascia.
• Insertion: Attaches to the transverse processes of the thoracic vertebrae, and inferior 9th or 10th rib nearest to angles.

Action: Acting with the Longissimus Cervicis, it extends the vertebral column; flexes it to one side; and pulls the ribs inferiorly.

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Nerve Supply: Dorsal primary rami of the spinal nerves.

Nerve Entrapment: Entraps the dorsal rami of the spinal nerve. Individuals complaining of this nerve entrapment may have symptoms of decreased or increased sensitivity or pain to the skin of the back.

Vascular supply: Intercostal and lumbar arteries, muscular branches of the occipital, and the deep cervical branches of the costocervical trunk arteries.

• Primary: Travell and Simons note two triggers in the Longissimus thoracis. The most superior trigger is located approximately at the level of the 11th rib, slightly lateral to the head. This trigger refers pain down the low back, deep into the buttocks to the level of the gluteal fold and medially to the cleft. The more inferior trigger is located at approximately the level of the 12th rib, directly over its head, and refers pain inferiorly through the lumbar region and to the superior aspect of the buttock.
• Satellite or associated triggers: Latissimus dorsi, Quadratus lumborum, Serratus posterior superior/inferior, contralateral superficial muscles, and Psoas.

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Trigger Point Signs and Symptoms: There is difficulty rising from a chair, with pain in the low back, and in the buttock region.

Trigger Point Activating and Perpetuating Factors: Sudden overload of the back, bending and twisting while lifting an object, Acceleration/Deceleration injury of the low back, prolonged riding in a car or plane.

Differential Diagnosis: Degenerative disc disease, (Segmental, Subluxation, Somatic dysfunction) Lumbar Radiculopathy (Bulging Prolapsed, Herniated Disc), Iliac aneurysm, Sprain/Strain Syndrome, Subacute meningitis, Intervertebral or Vertebral stenosis, Polymyalgia rheumatica, Fibromyalgia, Trochanteric bursitis, Sacral nerve compression (Sciatica), Polymyositis, Systemic lupus erythematosus, Osteoporosis, Osteoarthritis, Tumor, Lumbar Spine Hyperlordosis, Thoracic Spine Hyperkyphosis, Scoliosis, Ankylosing spondylitis, Rib Subluxation (Slipping Rib Syndrome), Gynecological disorders, Pregnancy, Cauda equina, Hip pointer, Hip dislocation fracture, Pulled Hamstring, Prostrate disorders, Tetanus, Systemic infections or inflammation, Nutritional inadequacy, Metabolic imbalance, Toxicity, Side effects of medication.

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