Deep Back Muscles Anatomy

Deep Back Muscles

• The transverso spinalis muscle group is a deep layer of back muscles, located between the vertebrae.
• It helps with back extension and likely proprioception.
• The transverso spinalis muscle group consists of three subgroups: semi spinalis, multifidus, and rotatores.
• Semi spinalis:
  • Most superficial and lateral of the transverso spinalis group.
  • Crosses 4-6 vertebrae.
  • Has different subdivisions:
    • Semispinalis capitis: Inserts into the head.
    • Semispinalis cervicis: Inserts into the neck.
    • Semispinalis thoracis: Inserts into the thorax vertebrae.
• Multifidus:
  • Deeper and more medial than semi spinalis.
  • Crosses 2-4 vertebrae.
  • Also has different subdivisions:
    • Multifidus capitis: Inserts into the head
    • Multifidus cervicis: Inserts into the neck
    • Multifidus thoracis: Inserts into the thorax vertebrae
    • Multifidus lumborum: Inserts into the lumbar vertebrae.
• Rotatores:
  • The deepest and most medial of the transverso spinalis group.
  • Crosses 1-2 vertebrae.
  • Also has different subdivisions:
    • Rotatores longus: Crosses two vertebrae
    • Rotatores brevis: Crosses one vertebra.

Other Deep Back Muscles

• Additionally, there is another minor deep layer of back muscles called the minor deep group.
• The minor deep group consists of three muscles:
  • Interspinalis: Between adjacent spinous processes.
  • Intertransversarii: Between adjacent transverse processes
  • Levator costarum: From the transverse process to a rib, and has two subdivisions:
    • Levator costarum brevis: Short, crosses one segment
    • Levator costarum longus: Longer, crosses two segments.

Function of Deep Back Muscles

• Deep back muscles contribute significantly to proprioception.
• Proprioception: The body’s awareness of its position and movement in space.
• They are packed with muscle spindles, making them critical for sensing vertebral position and movement.
• In case of spinal injury, these muscles may go into spasm to protect the back.

Importance of Core Strength

• Maintaining strong core muscles, including the abdominal muscles, is important for back health.
• These muscles contribute to back strength and stability.
• Correct lifting technique involves using the legs, not the back, to lift heavy objects and keeping the back neutral.

Terminology

• Deep muscles of the back are also known as intrinsic muscles of the back, located within the back itself.
• The erector spinae muscle group aids in back extension and is also considered an intrinsic back muscle.
• Deep back muscles may be considered a deep layer of intrinsic back muscles, while the erector spinae is sometimes an intermediate layer.

Important Points to Remember

• Proper lifting technique: Use legs, not back, when lifting heavy objects, keeping the back neutral.
• Warm up: Warm up core muscles before strenuous activity.
• Importance of core strength: Strong core muscles support the back.
• Protecting your back: Avoid lifting with a bent back and maintain good posture.

Test your knowledge on the anatomy of the deep back muscles, specifically the transverso spinalis group. This quiz covers the functions, subdivisions, and locations of the semi spinalis and multifidus muscles. Perfect for students of anatomy and physiology or anyone keen to learn about back muscles.