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.

Iliocostalis Thoracis

The Iliocostalis Thoracis is a deep muscle of the back.

Anatomical Attachments:

• Origin: Attaches to the angles of the inferior 6 ribs, and medially to the insertion of Iliocostalis lumborum.
• Insertion: Attaches to the upper borders of the angles of the first 6 ribs and to the transverse process of the 7th cervical vertebra.

Action: Collectively, extends, laterally flexes and rotates the spinal column, laterally moves the pelvis.

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Nerve Supply: Posterior rami of 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.

• Primary: Mid thoracic region – The pain refers upward toward the shoulder and laterally to the chest wall (which, if on the left side, can be mistaken for Angina); Low thoracic region – The pain refers upward across the scapula, around to the abdomen (commonly mistaken for visceral pain), and downward over the lumbar area.
• Satellite or associated triggers: Quadratus lumborum, Latissimus dorsi, Serratus posterior inferior, and Serratus posterior superior.

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Trigger Point Signs and Symptoms: The pain usually originates at the mid-back, inferior angle of the scapular, or at the lateral aspect of the sternum along the nipple line.

Trigger Point Activating and Perpetuating Factors: Sudden overload of the back, bending and twisting while lifting an object, acceleration/deceleration injury of the mid-thoracic region (whiplash), prolonged riding in a car or a plane.

Differential Diagnosis: Angina Pectoris, Myocardial infarction, Degenerative disc disease, (Segmental, Subluxation, Somatic dysfunction) Thoracic or Lumbar radiculopathy (Bulging Prolapsed, Herniated Disc), Spinal nerve compression, Rib subluxation (Slipping Rib Syndrome), Pulmonary neoplasm, Spinal cord tumor, Intervertebral or Vertebral stenosis, Sprain/Strain of the thoracic or lumbar spine (Mechanical overload or Acceleration/Deceleration injury), Osteoporosis, Osteoarthritis, Thoracic Spine Hyperkyphosis, Scoliosis, Ankylosing spondylitis, Vertebral compression fracture, Subacute meningitis, Cauda equina, Polymyalgia rheumatica, Fibromyalgia, Polymyositis, Systemic lupus erythematosus, Herpes zoster, Tetanus, Systemic infections or inflammation, Nutritional inadequacy, Metabolic imbalance, Toxicity, Side effects of medication.

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