The document describes the various muscles of the back, including their origins, insertions, innervation, and actions. It discusses the superficial, intermediate, and deep back muscles, categorizing them as extrinsic or intrinsic muscles. Key muscles described include the trapezius, latissimus dorsi, erector spinae group, rotatores, multifidus, semispinalis, and the suboccipital muscles.
Branches/roots from L4-L5-S1 join and become superior gluteal nerve giving motor supply to abductor muscle of gluteus medius and gluteus minimus
Branches/roots from L5-S1-S2 join and form inferior gluteal nerve giving motor supply to gluteus maximus, this muscle has 2 function for extension and external rotation of the hip
Branches/roots from L4-L5-S1 join and become superior gluteal nerve giving motor supply to abductor muscle of gluteus medius and gluteus minimus
Branches/roots from L5-S1-S2 join and form inferior gluteal nerve giving motor supply to gluteus maximus, this muscle has 2 function for extension and external rotation of the hip
2. Muscles of back
• Introduction
• Cutaneous nerve supply
• Development of muscles
• Muscles of back
Introduction
Classification
• Nerve supply of muscles of back
• Action of muscles of back
3. Cutaneous Nerves
• Dorsal primary rami of
spinal nerves.
• Each dorsal primary ramus
divides into medial and
lateral branches.
4. Muscles of back
Development:
• Epaxial muscles: Extensors
of the neck and vertebral
column
• Hypaxial muscles: Thoracic
myotome form lateral and
ventral flexor muscles of
the vertabral
column,lumbar myotome
form quadratus lumborum.
5. Arrangement of Back Muscles
• Three groups:
Superficial:
Extrinsic.
Intermediate:
Extrinsic.
Deep:
Intrinsic.
7. Thoracolumbar Fascia
• Deep fascia on the back of
trunk.
• It binds long exetonsors of
vertabral column to
posterolateral surfaces of
vertabral bodies.
• Two parts :Lumbar
Thoracic
8. Thoracolumbar Fascia Laminae
• Posterior lamina to lumbar
spinous processes.
• Middle lamina to lumbar
transverse processes.
• Anterior lamina (deepest) to
lumbar transverse processes.
9. Superficial Extrinsic Muscles
• Connect limb to axial skeleton.
• Innervated by ventral rami or CN XI.
• Include:
Trapezius.
Latissimus dorsi.
Levator scapulae.
Rhomboideus major.
Rhomboideus minor.
15. Intrinsic Back Muscles
• True intrinsic muscles of the back are innervated by dorsal
(posterior) rami.
• Three groups:
Superficial
Intermediate
Deep.
17. Superficial muscles
• Consists of the Splenius group:
• Long muscles.
• Originate from ligamentum nuchae and spinous processes.
• Cover neck and upper part of thorax.
• Two parts: Splenius capitis
Splenius cervicis
19. Superficial Intrinsic
Erector spinae: Three muscles
each with three regional
parts.
1.Spinalis:Spinalis thoracis
Spinalis cervicis
Spinalis capitis
2.Longissimus:Longi capitis
Longi cervicis
Longi thoracis
3.Iliocostalis:Iliocost cervicis
Iliocost thoracis
Iliocost capitis
24. Deep Intrinsic Muscles
• Spinotransverse group:
Present between
spinous process and
transverse elements of
vertebrae.
Components:
Rotators: Rotators thoracis
Rotators cervicis
Rotators capitis
Multifidus
Semispinalis: Semi cervicis
Semi thoracis
Semi capitis
Suboccipital muscle
25. Rotatores
• Deepest and shortest muscle
• 11 pairs of small
quadrilateral muscle
• Attachments:
• Components:
Rotator brevis:
Attachments
Rotator longus:
Attachments
26. Multifidus
• Thick muscle mass.
• Present at
cervical,thoracic,upper
lumbar levels lies lateral
to spinous process and
also expands to cover
posterior surface of
sacrum.
• Multifidus arises from
lateral surface and tip of
trnsverse process and
insert into transverse
elements of vertebrae.