Download Trunk

Kinesiology
of the Trunk
and Spine
Osteology of the Trunk and Spine
• Vertebral column: 24 articulating vertebrae
7 cervical
12 thoracic
5 lumbar
sacrum (5)
coccyx (4)
Vertebrae
Vertebrae increase in size from superior to inferior
C1 and C2: atlas and axis
Spinal curves:
secondary: cervical and lumbar
primary: thoracic and sacral
Spinal curvature deformations:
lordosis, kyphosis, and scoliosis
Primary spinal curves (thoracic and sacral) are a result
of body position during fetal development.
Vertebrae
Landmarks: body, vertebral foramen, spinous
process, transverse process, articular facets,
costal facets.
Vertebral joints: motion segment
Atlanto-axial joint: pivot joint at C1 and C2.
Atlanto-occipital joint: base of skull and C1
Vertebral disks: annulus fibrosus and nucleus
pulposus.
Herniated disks: protrusion of nucleus
pulposus
Thorax
12 pairs of ribs
7 pairs of true ribs (attach to sternum)
5 pairs of false ribs
-3 pairs attach indirectly to sternum
-2 floating ribs
Manubrium
Sternum
Xiphoid process
Ribs attach to vertebrae at the costal facets
Movements of the trunk and spine
• Spinal flexion (lumbar, trunk, cervical flexion):
forward movement.
• Spinal extension (lumbar, trunk, cervical
extension): return movement posteriorly.
• Lateral flexion (cervical or trunk) left or right side
bending.
• Spinal rotation (trunk or cervical): left or right
rotation .
• Reduction: return movement from lateral flexion.
Muscles of the trunk and spine
Splenius Cervicis
O: SP T3-T6
I: TP C1 - C3
A: Cervical extension (both ),
rotation, cervical lat. Flex.
Splenius Capitis
• O: ligamentum nuchae, SP C7-T-3
• I: Mastoid process and occipital bone
• A: Cervical extension, rotation, cervical
lateral flexion.
Sternocleidomastoid
• O: Manubrium, middle of clavicle
• I: Mastoid process
• A: Cervical flexion, rotation, lateral flexion
Erector Spinae Group:
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Iliocostalis: Lateral layer
Longissimus: Middle layer
Spinalis: medial layer
A: Trunk (spinal) extension,
lateral flexion
Rectus Abdominus
• O: Crest of the pubis bone (pubic crest)
• I: Cartilage of ribs 5-7, xiphoid process
• A: Lumbar (trunk) flexion, lateral flexion
External oblique
• O: Lower 8 ribs, dovetailing with serratus
anterior
• I: crest of ilium, inguinal ligament,
crest of pubis, fascia of
rectus abdominus
• A: Lumbar flexion,
lateral flexion, rotation of trunk
Internal oblique
• O: Upper 1/2 of inguinal ligament, iliac
crest, lumbar fascia
• I: Costal cartilages of ribs 8-10,
linea alba
• A: lumbar flexion,
lateral flexion, rotation of trunk
External Oblique
Transversus abdominus
• O: Inguinal ligament, iliac crest, cartilage of
lower 6 ribs, lumbar fascia.
• I: Pubic crest, iliopectineal line,
abdominal aponeurosis to linea alba
• A: Compresses abdomen
(sucks in gut), forced expiration
Quadratus lumborum
• O: Iliac crest
• I: Bottom of rib 12, TP L1-L4
• A: Lateral flexion, stabilizes lower back