Biomechanics Spine
The rotation of the C2 vertebrae accounts for
1/2 of cervical rotation
How many thoracic vertebrae are there?
12
Which ribs are articulate with 1 vertebrae?
1st 10-12th
How many floating ribs are there?
2 NO CARTILAGINOUS ATTACHMENT
All other ribs are articulate with how many vertebrae?
2 adjacent
C1 or Atlas vertebrae allows how many degrees of what plane of motion?
20-30 sagittal plane
During exercise, the rib cage expands in how many planes?
3
What is the angle of facets?
45 degrees
Articulation-Cervical vertebral arch
45 degrees FAVORS ROTATION + LATERAL FLEXION
How many false ribs are there?
5
How many lumbar vertebrae are there?
5
How many cervical vertebrae are there?
7
How many true ribs are there?
7
C2 or Axis vertebrae
ATYPICAL VERTEBRAE ROTATION (50 DEGREES) FLEXION / EXTENSION (15 DEGREES)
What is found around the nucleus pulposus?
Annulus fibrosus
Upper C-spine
Capital Flexion / Extension (C1 + C2)
What are the functions of a disc?
Contract Distract Handle shear stress
Degenerative Disc Disease
Discs whither away as we age
Tripod of vertebrae
Facet Facet Body
Why isnt T-spine rotation limited?
Facets give us rotation Ribs help not restrict any rotation
Anterior levator scap
Flex
Cervical Spine & Atlanto-Occipital Joint muscular action to move the spine:
Flexion Extension & Hyperextension Lateral flexion / Side bending Rotation
T-spine motions:
Flexion (30-40) / Extension (20-25) Rotation (60) Long spine board (50)
Movements of the Thorax
Increase in transverse diameter increase in anteroposterior diameter increase in vertical diameter
Gross ROM of C-spine
Long Flexion (35-70) / Extension (45-70) Rotation (90-120) LSB (40-50)
What is the normal resting position of the C-spine?
Lordotic 30 degrees
When doing a chin tuck, what motions are occuring?
Lower Extension Upper Flexion
How do the facets in the T-spine compare to those in the C-spine?
More vertical 75 degrees
Is there a disc found between C1 and C2?
NO
Do upper and lower C-spine work togther?
NO WORK OPPOSITE OF EACH OTHER
C1 or Atlas vertebrae
NO SPINOUS PROCESS NO BODY LARGE SUPERIOR FACETS TRANSVERSE PROCESSES
Is there alot of movement in the thoracic region? Why are there such little injuries heard of in the thoracic region?
NOT ALOT OF MOVEMENT = NOT A LOT OF INJURIES
No discs are found between
O-C1
Factors that influence stability and motion:
Pressure + Tension stress Anteroposterior Curves Relative Thickness and Shape of Discs Thickness and Strength of Ligaments Direction + Obliquity of Articular Facets Size + Obliquity of Spinous process Articulations of ribs with vertebrae
Sternocleidomastoid helps to
Protract neck
What plays a huge role in the support of the T-spine?
Ribs
Muscles of the C-spine: Semispinalis Thoracis / Cervicis / Capitis
Singly: Lateral flexion & rotates spine to opposite side Together: Extend & hyperextend thoracic and cervical spine
Muscles of the C-spine: Splenius Capitis + Cervicis
Singly: Laterally Flex head and neck & rotate to same side Together: Extend and hyperextend head & neck
Muscles of the C-spine: Prevertebral muscles
Singly: Laterally flex & rotate to opposite side Together: Flex head & neck
Muscles of the C-spine: Sternocleidomastoid
Singly: Laterally flex head & neck and rotate to opposite side Together: Flex neck and head
Muscles of the C-spine: Scalenus Anterior / Posterior / Medius
Singly: Laterally flex neck Together: Flex cervical spine
Muscles of the C-spine: Levator Scap
Singly: Laterally flex neck Together: Stabilize neck
Semispinalis Cervicis
Spine mover
Muscles used for extension & Hyperextension of the spine
Splenius capitis & cervicis Erector spinae capitis & cervicis Semispinalis
Muscles used for lateral flexion / side bending of spine:
Splenius capitis & cervicis Erector spinae Semispinalis Scalenes Sternocleidomastoid
Muscles used for spine rotation
Sternocleidomastoid Splenius Erector spinae Occipitalis
Muscles used for spine flexion
Sternocleidomastoid Scalenes Pre-vertebral muscles
What are the kinds of sternocostal joints?
Sternocostal Costochondral Interchondral Intersternal
Anatomy of the rib cage
Sternum Bony-cartilaginous cage Thoracic vertebrae (12) True / False / Floating ribs
What are the functions of the C-spine?
Supports head Protects spinal cord Shock Absorber Provides attachment for key muscles Provides ROM for increased visual field
Coupled T-spine motions
TSB + rotation Upper: ipsilateral Lower: contralateral
What having forward head posture, what motions are occurring?
Upper extension Lower Flexion
Discs permit compression in _________ direction and some torsion
any
C1 vertebrae
atlas
C2 vertebrae
axis
Where is the first disc found in the vertebrae?
betwn C2-C3 SMALLEST DISC
How are discs labeled?
by the vertebrae they fall between C3/4 L4/5
MUSCLE OF THE C-SPINE: SUBOCCIPITAL GROUP
capital movers (to move head) Singly: LATERALLY FLEX OR ROTATE HEAD Together: EXTEND HEAD
each facets has what to be able to move?
capsule
Upper thoracic acts like
cervical
Facets
change in angle all down the spine
Coupled motions of the spine
consistent association of 1 motion about axis with another motion around a DIF axis WHEN WE SIDE BEND, OUR VERTEBRAE ROTATES IN THE SAME DIRECTION
Discs are found between
each vertebrae
The scalenus anterior helps to
elevate upper ribs in forced inspiration
Posterior levator scap
extend
Discs are made of
fibrocartilage
Movements of the articulation-cervical vertebral arch
flexion lateral flexion hyperextension rotation
semispinalis capitis
head mover
What do anteroposterior curves do?
influence the nature + degrees of motion in dif regions
As you travel down the vertebrae, the discs AND tripods get
larger
The right sternocleidomastoid rotates the neck
left
What are the curves of the spine?
lordotic and kyphotic
Flexion and extension is greater in the upper/lower thoracic
lower
LSB or long spine board is greater in the upper/lower thoracic?
lower
Lower thoracic acts like
lumbar
The younger we are, what happens to our discs?
more flexible
Myotomes
motor fibers
What is found in the center of a disc?
nucleus pulposus
Nonaxial joints
permits gliding
Lower C-spine
rest of spine
The left sternocleidomastoid rotates the neck
right
Dermatomes =
sensory fibers
Discs are used as
shock absorbers
What is the limiter for T-spine extension?
spinous process
Dens
superior boney projection from the vertebra
The anterior portion of the C2 vertebrae extends
superiorly
Discs push what apart?
vertebrae
Ligaments pull what together?
vertebrae
Spinous process of vertebra
what we can feel in the back
