Module 2.3 Flashcards
The Vertebral Column is composed of:
7 Cervical 12 Thoracic 5 Lumbar 5 Fused Sacral 4 Fused Coccygeal 2 Primary Curves 2 Secondary Curves
Curves
Infant: 1 primary convex curve
Adult: 2 secondary concave curves
Cervical – as the baby hold its head up
Lumbar – as the child starts to walk upright
3rd or 4th month: concave curve develops
As the child walks: lumbar concave curve develops
is an exaggeration of the thoracic curvature, which may occur in the aged due to osteoporosis or disc degeneration
KYPHOSIS
is an exaggeration of the lumbar curvature, which may occur as a result of pregnancy, spondylolisthesis, or “pot belly.”
LORDOSIS
is a complex lateral deviation/torsion, which may occur due to poliomyelitis, a short leg, or hip disease.
SCOLIOSIS
True or False
There is a physiologic Kyphosis and Lordosis, but Scoliosis is ALWAYS pathologic
True
Parts Of A Typical Vertebrae
Body – Anteriorly
Vertebral Canal
Lamina – “roofs”
Pedicles – “walls”
Typical Vertebrae: 7 Projections
o (1) SPINOUS PROCESS- posteriorly
o (2) TRANSVERSE PROCESSES- laterally
o (2) SUPERIOR FACETS-facing dorsally
o (2) INFERIOR FACETS-facing ventrally
MOTION SEGMENT: 3 Joints
Intervertebral Disc
• Synarthroses (bone – connective tissue – bone)
• Cartilage joint
2 Facet joints
• Diarthroses (bone – joint capsule – joint)
• Synovial joint
o Half the height of corresponding body forming a superior and inferior notch
o Adjacent inferior and superior notches form the intervertebral foramen thru neural and vascular structures pass
Pedicles
- “Circular life preserver with a beach ball at the center”
INTERVERTEBRAL DISC
FACET JOINT ORIENTATION
Cervical facets are more on the transverse plane-allowing more head rotation
Thoracic facets are on the coronal plane-allowing more trunk lateral flexion
Lumbar facets are more on the sagittal plane- allowing more trunk flexion/extension
Motion Segment: 6 LIGAMENTS
- Anterior longitudinal ligament
- Posterior longitudinal ligament
- Ligamentum flavum
- Intertransverse ligament
- Interspinous ligament
- Supraspinous ligament
- Strong, dense anterolateral band from sacrum to C2 and atlanto-occipital ligament (from C2 to the head)
- Twice stronger than PLL
- Function: limits extension
ANTERIOR LONGITUDINAL LIGAMENT (ALL)
- Narrow posterior band from sacrum to C2 and tectorial membrane (from C2 to the head)
- Allows posterolateral disc herniation
- Function: limits flexion
POSTERIOR LONGITUDINAL LIGAMENT (PLL)
- Paired yellow elastic bands from ventral surface of upper lamina to upper lip of lower one
- Bridges spaces between adjacent laminae (superior and inferior laminae)
- Central gap facilitates anesthetic needle passage in lumbar punctures
- In constant tension even when spine in neutral
LIGAMENTUM FLAVUM
- Small, but well developed in lumbar area
INTRATRANSVERSE / INTERSPINOUS LIGAMENTS
- From sacrum to C7, ligamentum nuchae
- Among earliest to fail in hyperflexion
SUPRASPINOUS LIGAMENT
High water & proteoglycan contents
o Proteoglycan = glycosaminoglycans (GAGs) + water
GAGs: o Chondroitin-4-sulfate o Chondroitin-6-sulfate o Hyaluronate o Keratan sulfate
Lower collagen (type II-better for compression) content
Central nucleus
- higher collagen (type I-higher resistance to tension) content; arranged in concentric lamellae
- attached to the vertebral cartilaginous endplates, epiphyseal ring (Sharpey’s fibers), vertebral body periosteum, longitudinal ligaments
Peripheral annulus
- Peripheral “life preserver”
- Low water
- Higher collagen fibers in concentric lamellae
- Type I collagen (for tension)
ANNULUS FIBROSUS/ PERIPHERAL ANNULUS
- Central “beach ball”
- Higher water and proteoglycans
- Lower collagen
- Type II collagen (for compression)
NUCLEUS POLPOSUS/ CENTRAL NUCLEOUS
CHANGES WITH AGE (Degenerative Changes)
DISC- “circular life preserver with beach ball at the center”
loss of water content
loss of proteoglycans which maintain disc hydration
FACET JOINTS
Osteophyte formation
Joint capsule thickening
LIGAMENTUM FLAVUM
thickening
- Narrowing of the neural foramen and spinal canal
- Compression of neural elements
- Instability of the motion segment
- Diagnosis is RAYUMA.
o Spinal stenosis
o Degenerative osteoarthritis
o Spondylosis
END RESULT = BACK PAIN +/- NUMBNESS/PARESTHESIAS OF LEGS
- Improper back use exceeding tensile strength of fibers
- Tears=back pain
- Healing of tear=symptom relief but weaker disc
- Continued improper back use
- Tears getting bigger
- Unable to hold beach ball in the middle
- Strong PLL posteriorly
- Ball “slips” posterolaterally
DISC HERNIATION
DISC HERNIATION: Clinical Tests
- bent leg
Kernig’s sign
DISC HERNIATION: Clinical Tests
- flexing head, coughing, sneezing, shock-like sensation down extremities
Lhermitte’s
DISC HERNIATION: Clinical Tests
- flexing head, px adducts and flexes knee
Brudzinski’s
DISC HERNIATION: Clinical Tests
- straight-leg
Laseague’s sign
DISC HERNIATION: Clinical Tests
-crossed straight-leg raising
Fajerstajn’s
- Transverse diameter > AP diameter
- Has transverse foramina in the transverse process where vertebral artery passes
- Transverse process has anterior and posterior tubercles (attach cervical muscles)
- Uncinate processes on the supero-lateral body to add stability
CERVICAL VERTEBRAE
- Bifid spinous process for muscle attachments
- Facets oriented in an up-down direction (transverse plane)
- Superior facing upward and posteriorly
- Inferior facing downward and anteriorly
- Allows high degree of mobility (rotation and flexion/extension)
CERVICAL VERTEBRAE
- means carries the globe (head) alone
- No body, no spinous process (ring),
- Has 2 lateral masses
- All facet joint surfaces are concave
ATLAS (C1)
- Has a dens (or odontoid process) – “projects like an axis”
- Has large thick laminae since the weight of the head is transmitted directly from the atlas
AXIS (C2)
- Synovial joint composed of 2 concave superior facets of the atlas and 2 convex occipital condyles of the skull
- Allows head nodding - “O-O”
AtlantO-Occipital joint
- Synovial joint that allows head turning side-to-side – “Ah-Ah”
- Large free space for cord to lessen impingement during cervical motion
- Ligaments and joint capsules are lax
- Muscles provide most of the stability
Atlanto-Axial (AA) joint
- Vertebra Prominens (because it has the most prominent spinous process)
- Has the longest spinous process
- Spinous process is not bifid
C7
- Articulates with paired ribs
- Demifacets – facets on transverse process and body
- Rib cage limits motion
- is the most stable because it has rib cage
- Facets oriented in the coronal plane allowing lateral rotation
- Spinous process is long and oriented inferiorly limiting extension.
THORACIC VERTEBRAE
- Has massive body to support weight of upper body
- Facets oriented along sagittal plane
LUMBAR VERTEBRAE
BODY: small
SUPERIOR FACET ORIENTATION: superiorly and medially
INFERIOR FACET ORIENTATION: inferiorly and laterally
TRANSVERSE PROCESS: foramen for vertebral artery
SPINOUS PROCESS: bifid
Cervical
BODY: equal transverse and AP diameter; demifacet for ribs
SUPERIOR FACET ORIENTATION: supero-posteriorly and laterally
INFERIOR FACET ORIENTATION: anteriorly and medially
TRANSVERSE PROCESS: demifacet for ribs
SPINOUS PROCESS: slopes inferiorly and overlaps with adjacent process
Thoracic
BODY: massive
SUPERIOR FACET ORIENTATION: concave; medially and posteriorly
INFERIOR FACET ORIENTATION: anteriorly and laterally
TRANSVERSE PROCESS: long and slender
SPINOUS PROCESS: broad and thick
Lumbar
- 5 fused vertebrae
- Triangular complex supporting the spine and posterior wall of the pelvis
- Concave and very smooth anteriorly and tilted towards the back (sacro-vertebral angle)
- Laterally projecting alae are the fused anterior costal and posterior transverse processes of S1 to S3 and articulate with the iliac bone of either side (sacro-iliac joints)
Sacrum
- 4 ligaments-strong and taut; prevents separation of the ilium from the sacrum on erect posture
- ½ bodyweight passes thru from L5 and S1 then down each extremity during bipedal stance
- Ligaments soften during pregnancy to allow childbirth
Sacro-iliac joint
- 4 vertebral rudiments
- Contributes no supportive function to the spine
- Serves as an origin for the gluteus maximus posteriorly and the pelvic diaphragm anteriorly
COCCYX
- Bilateral muscles located anterior and lateral to the spine
- Attach to the ribs, sternum and pelvis
- Will flex structures forward if acting bilaterally
- Will flex laterally if acting unilaterally
- Act indirectly on the vertebral column by pulling on adjacent structures (e.g. pulling pelvis to the ribs as in a sit up flexes the lumbar spine)
- Not active during normal erect standing
- Will contract isometrically to stabilize the ribs and pelvis during pushing, pulling or lifting
SPINE FLEXORS
CERVICAL AND HEAD FLEXORS
- Scalenus anterior
- Scalenus medius
- Scalenus posterior
- Longus capitis
- Longus colli
HEAD FLEXORS
- Rectus capitis anterior
- Rectus capitis lateralis
LUMBAR FLEXORS
- Psoas major and minor
- Iliacus
- Quadratus lumborum
Anterior Abdominal wall muscles (attach ribs to pelvis) o Rectus abdominis o External oblique o Internal oblique
- Bilateral muscles located posteriorly and laterally in several layers
- Extends when acting bilaterally
- Laterally flexes or rotates when acting unilaterally
- Eccentric contraction controls extent and rate of forward flexion
- At a disadvantage if lifting in a forward flexion due to greater moment by gravity, requires more forceful contractions, increasing intradiscal pressure
SPINE EXTENSORS
SPINE EXTENSORS
Erector Spinae (S-I-LO): Spinalis (upper 80%, interspine connection) , Iliocostalis (lower 80%, transverse process, rib to rib, or ilium), LOngisimus (connects trans processes)
Transversospinalis (SMR)-Semispinalis (superficial & extends), Multifidus (intermediate), Rotatores (deepest and rotates)
SPINE EXTENSORS (DEEPEST LAYER)
- Interspinalis
- Intertransvarii
- Very strong
- Transfers weight from the axial skeleton to the lower extremity during stance
- Supports body weight while standing
- Serves as attachment of powerful trunk and lower extremity muscles
BONY PELVIS
Pelvis: 4 Bones
- paired hip, hemipelvic or inominate bones- from 3 separate (infant) and eventually fused (puberty) bones: ilium, ischium and pubis
- sacrum- from 5 fused sacral vertebrae
- coccyx- from 4 fused rudimentary coccygeal vertebrae
INNOMINATE BONE
- Ilium Crest
- Pubis
- Ischium
Joints of the pelvis
Symphyses
- lumbosacral joint
- sacrococcygeal joint
pubic symphysis
- Synovial joint
- sacro-iliac joint
- Paired plane synovial joints that unite the hemipelvis to the sacrum posteriorly on either side
- Very strong slightly movable weight-bearing joints reinforced by interlocking bone ends; interosseous ligaments and anterior and posterior sacro-iliac ligaments
Sacro-iliac joints
- joins the 2 innominate bones in front
- symphysis (secondary cartilaginous joint)- slightly movable midline joint whose bone ends are united by fibrocartilage
Symphysis pubis
Ligaments are relaxed by increase in sex hormones and the peptide hormone __ from the corpus luteum during menstruation and pregnancy.
relaxin
Joints become less bound resulting in more motion causing a 10-15 degree increase in the transverse diameter of the pelvis commonly causing __
back pain
- pelvic brim (edge of the inlet) which has a 55 degree angle with horizontal
- coincides with a line from the superior pubis to the sacral promontory, conjugate diameter (AP) of the pelvis
Pelvic inlet
Pelvic inlet: Borders
- pubic symphysis, pubic crest, pecten pubis
- arcuate line of ilium
- sacral ala, sacral promontory
Pelvic Outlet: Borders
- inferior margin of pubic symphysis, inferior ramus of pubis
- ischial tuberosity
- sacrotuberous ligament
- tip of the coccyx
- superior to the inlet, inferior abdomen
- contains ileum and sigmoid colon
- anterior abdominal wall in front, iliac fossa at the sides, L5-S1 vertebrae at the back
Greater pelvis
- pelvic inlet separates it from greater pelvis
- between pelvic inlet and outlet
- contains bladder, uterus and ovaries
- enclosed by the innominate bones, sacrum and coccyx
Lesser pelvis
General structure: Thick and heavy Greater pelvis: Deep Lesser pelvis: Narrow and deep Pelvic inlet: Heart-shaped (android) Pelvic outlet: Smaller Pubic arch and subpubic angle: Narrow Obturator foramen: Round Acetabulum: Larger
Male Pelvis
General structure: Thin and light Greater pelvis: Shallow Lesser pelvis: Wide and shallow Pelvic inlet: Oval and rounded (gynecoid) Pelvic outlet: Larger Pubic arch and subpubic angle: Wide Obturator foramen: Oval Acetabulum: Smaller
Female Pelvis
- forms the contour of the buttocks, crosses 1 joint
main hip extensor (with the hamstrings), superior portion abducts the hip, inferior portion adducts the hip, laterally rotates hip - very active (with the hamstrings) during walking by slowing hip flexion at the end of swing and in pulling the trunk over the stance limb at early stance
Gluteus maximus
well-developed Gluteus maximus in athletes cause tightness and may force the trunk to hyperflex in squatting and tying shoes leading to __
low back pain
- main hip abductor
- keeps pelvis level in a unilateral stance
anterior and middle portions medially rotate the hip - posterior portion laterally rotate the hip
Gluteus medius
- Anteroposterior compression of the pelvis occurs during crush accidents (when a heavy object falls on the pelvis)
- Commonly produces fractures on the pubic rami
- When the pelvis is compressed laterally, the acetabula and ilia are squeezed toward each other and may be broken
- Below 17 years old: Acetabulum may fracture through the triradiate cartilage into its 3 developmental parts or the bony acetabular margins may be torn away.
Pelvic Fractures
Weak areas of the pelvis (where fractures often occur):
o Acetabulum
o Pubic ramus
o Region of sacroiliac joints
o Alae of ilium
Powerful rotators and joint surface compressors because of their almost perpendicular line of action to shaft of femur
Six short lateral rotators
Nerve Innervation of Gluteus medius and Gluteus minimus
superior gluteal nerve
Nerve innervation of Gluteus Maximus
inferior gluteal nerve
(Short hip lateral rotators)
Nerve innervation of Obturator internus and externus, Superior and inferior gemilli and Quadratus femoris
spinal nerves L5 and S1
(Short hip lateral rotators)
Nerve innervation of Piriformis
spinal nerves S1 and S2
- Hip extensors, knee flexors, leg rotators
- Innervated by the Sciatic nerve (tibial division) except short head of biceps femoris which is supplied by the common fibular division
- Muscles:
o Biceps femoris (long and short head)
o Semimembranosus
o Semitendinosus
Posterior thigh muscles
- attaches to fibular head, lateral leg rotator
Biceps femoris
- attaches to medial tibia, medial leg rotator
Semimembranosus and Semitendinosus
- Ventral rami of L4-S3
- Actually 2 nerves loosely joined by common connective tissue: Tibial and Common fibular nerves
- Largest nerve in the body
- With its own artery from the Inferior gluteal artery
- Supplies the skin and muscles of the foot, leg, and posterior thigh
- Variations occur as to how it passes the piriformis muscle
Sciatic Nerve