Week 10 - Back Muscles & Ergonomics Flashcards
What are the components of the vertebral column?
Cervical: 7, Thoracic: 12, Lumbar: 5, Sacral: 5 (fused), Coccygeal: 4 (fused)
Total = 33 (counted as 26 due to fusion)
What movements can occur at the vertebral column?
- Flexion: bending forward
- Extension: bending backward
- Lateral flexion: bending sideways
- Rotation: twisting the trunk
What are the functions of the vertebral column?
- Protects the spinal cord & spinal nerves
- Supports body weight above the pelvis
- Provides a rigid & flexible axis
- Plays a role in posture & locomotion
What are the layers of extrinsic muscles of the back?
- 1st layer: Trapezius, Latissimus Dorsi
- 2nd layer: Levator Scapulae, Rhomboids (minor & major)
- 3rd layer: Serratus posterior (superior & inferior)
What are the superficial extrinsic back muscles?
- Trapezius
- Latissimus dorsi
- Levator scapulae
- Rhomboids major & minor
What is the function of the trapezius muscle?
Attaches the pectoral girdle to the cranium and vertebral column, assists in suspending the upper limb.
What forms the triangle of auscultation?
- Superiorly and medially: Trapezius
- Inferiorly: Latissimus dorsi
- Laterally: Medial border of the scapula
What is the floor of the inferior lumbar triangle?
Internal oblique muscle
What is the motor innervation of the trapezius?
Spinal part of accessory nerve (XI)
What actions are associated with the latissimus dorsi?
- Extension
- Adduction
- Medial rotation of the upper limb
What is the origin and insertion of the levator scapulae?
- Origin: Transverse processes of upper cervical vertebrae
- Insertion: Superomedial border of the scapula
What are the components of the erector spinae?
- Iliocostalis
- Longissimus
- Spinalis
What is the chief extensor of the vertebral column?
Erector spinae
What are the actions of the intrinsic back muscles?
- Maintain posture
- Control movement of the vertebral column
What are the superficial intrinsic back muscles?
- Splenius cervicis
- Splenius capitis
What are the components of the iliocostalis group?
- Iliocostalis cervicis
- Iliocostalis thoracis
- Iliocostalis lumborum
What are the components of the longissimus group?
- Longissimus capitis
- Longissimus cervicis
- Longissimus thoracis
What are the components of the spinalis group?
- Spinalis capitis
- Spinalis cervicis
- Spinalis thoracis
What are the major deep intrinsic back muscles?
- Semispinalis
- Multifidus
- Rotatores
What are the minor segmental deep layer muscles?
- Interspinales
- Intertransversarii
- Levatores costarum
What is the innervation of the intrinsic muscles of the back?
All are supplied by the posterior primary rami of spinal nerves.
Fill in the blank: The _______ group consists of semispinalis, multifidus, and rotatores.
Transversospinal
