Anatomy: Muscles of the Back

Study Notes

Anatomy: Muscles of the Back

1. Overview

Muscles of the back are primarily responsible for movement, stability, and posture.
They are categorized into three main groups: superficial, intermediate, and deep muscles.

2. Superficial Back Muscles

Trapezius
- Shape: Diamond or kite-shaped
- Functions: Elevates, retracts, and rotates scapula; extends neck.
Latissimus Dorsi
- Shape: Broad, flat muscle.
- Functions: Extends, adducts, and medially rotates the arm; assists in trunk movement.
Rhomboid Major and Minor
- Location: Between the spine and scapula.
- Functions: Retracts and elevates scapula.

3. Intermediate Back Muscles

Serratus Posterior Superior
- Location: Upper back.
- Functions: Elevates ribs during inhalation.
Serratus Posterior Inferior
- Location: Lower back.
- Functions: Depresses ribs during exhalation.

4. Deep Back Muscles

Erector Spinae Group (Iliocostalis, Longissimus, Spinalis)
- Functions: Extends and laterally flexes the vertebral column; supports upright posture.
Transversospinalis Group (Semispinalis, Multifidus, Rotatores)
- Functions: Stabilizes and rotates the vertebral column; aids in extension.

5. Muscle Innervation

Primarily innervated by the dorsal rami of spinal nerves.
Superficial muscles may receive innervation from cranial and cervical nerves.

6. Blood Supply

Supplied by branches of the posterior intercostal arteries, lumbar arteries, and the subclavian artery.

7. Clinical Relevance

Back muscles can be affected by strain, injury, or conditions like scoliosis.
Strength and flexibility exercises are crucial for back health and injury prevention.

Overview of Back Muscles

Back muscles play a vital role in movement, stability, and maintaining posture.
Three primary categories: superficial, intermediate, and deep muscles.

Superficial Back Muscles

Trapezius
- Shape resembles a diamond or kite.
- Functions include elevating, retracting, and rotating the scapula, as well as extending the neck.
Latissimus Dorsi
- Characterized as a broad, flat muscle.
- Responsible for extending, adducting, and medially rotating the arm; aids in trunk movement.
Rhomboid Major and Minor
- Positioned between the spine and the scapula.
- Primarily retracts and elevates the scapula.

Intermediate Back Muscles

Serratus Posterior Superior
- Located in the upper back region.
- Elevates ribs during inhalation.
Serratus Posterior Inferior
- Found in the lower back area.
- Functions to depress ribs during exhalation.

Deep Back Muscles

Erector Spinae Group (including Iliocostalis, Longissimus, Spinalis)
- Responsible for extending and laterally flexing the vertebral column; crucial for supporting an upright posture.
Transversospinalis Group (comprising Semispinalis, Multifidus, Rotatores)
- Stabilizes and rotates the vertebral column; aids in extension.

Muscle Innervation

Dorsal rami of spinal nerves primarily provide innervation to back muscles.
Superficial muscles may receive some innervation from cranial and cervical nerves.

Blood Supply

Back muscles receive blood from branches of the posterior intercostal arteries, lumbar arteries, and subclavian artery.

Clinical Relevance

Back muscles are susceptible to strain, injury, and conditions such as scoliosis.
Engaging in strength and flexibility exercises is essential for maintaining back health and preventing injuries.

Description

Test your knowledge on the anatomy of the back muscles. This quiz covers the superficial, intermediate, and deep muscle groups, including their functions and locations. Understand how these muscles contribute to movement, stability, and posture.