Spine - Kines

interconnected movement between adjacent vertebrae during different motions

Coupling

When you bend forward (flexion), your lumbar spine might also ________

Slightly rotate

functional unit of the vertebral column

Motion segment

Three joints of a Spinal Motion Segment

interbody joint and 2 facet joints

Components of a Motion Segment

two adjacent vertebral bodies, intervertebral disc and two facet joints

Disc thickness or size affects what?

Amount of motion

Facets orientation affect what?

Direction of motion

Arthrokinematic Motions of Flexion & Extension

Anterior-Posterior shear or slide

Arthrokinematic Motions of Lateral Bending

Lateral shear or slide

Arthrokinematic Motions of Rotation

Distraction or Compression

If the superior and inferior facets are oriented in the sagittal plane (i.e., lumbar) it permits more ____ and ____

Flexion & Extension

If the facets are oriented in the frontal plane (i.e., thoracic) it permits more_______

Lateral Flexion

if the facets are oriented in the transverse plane (i.e., cervical) it permits more _____

Rotation

Facet joints in the cervical spine are nearly parallel to the _____ plane

Frontal Plane (45 degrees frontal plane/more transverse)

Facet joints in the Thoracic spine are angled ____ and ______

Backward and Medially (60 degrees; frontal plane

Facet joints in the lumbar spine are oriented ________; _____ plane

90 degrees; sagittal plane

Facet joint orientation in the cervical region allows for what types of movements?

This allows for extensive flexion/extension, lateral bending, and rotation in the neck, crucial for head and neck mobility

Facet joints orientation thoracic region allows for what types of movements?

This restricts flexion and extension compared to the cervical spine but allows some lateral bending and rotation

Facet joints orientation lumbar region allows for what types of movements?

This design allows for significant flexion/extension but limits lateral bending and rotation

Kinematics of vertebra during Flexion

• Vertebral body (above) tilts anteriorly

• Inferior facet (above vertebrae) slides upward on the superior facet of the (below vertebrae)

• Separation of spinous process

• Widening of the intervertebral foramen

• Anterior portion of the annulus fibrosus is compressed

• Posterior portion of the annulus fibrosus is stretched

Kinematics of vertebra during Extension

• Vertebral body (above) tilts posteriorly

• Inferior facet (above vertebrae) slides downward on the superior facet of the (below vertebrae)

• Approximation of spinous process

• Narrowing of the intervertebral foramen

• Anterior portion of the annulus fibrosus is stretched

• Posterior portion of the annulus fibrosus is compressed

The vertebral column is prone to the following forces:

1. Axial compression/distraction

2. Shear

3. Torsion

rotation of the spinal column is always coupled with side-bending except for the _______

atlantoaxial joint

Lumbopelvic rhythm

1. Lumbosacral flexion

2. Anterior tilt of pelvis

3. Hip joint flexion

According to the lumbopelvic rhythm, when we bend forward, the erector spinae muscle contracts _______

Eccentrically

According to the lumbopelvic rhythm, when we bend forward, the hip flexors contract _______

concentrically

According to the lumbopelvic rhythm, when we bend forward, the hip extensors contract _______

eccentrically

Erector Spinae

1. Iliocostalis: cervicis, thoracis and lumborum

2. Longissimus: capitis, cervicis, thoracis and lumborum

3. Spinalis: Thoracis and lumborum

   Primary function: Back extension

Intrinsic back muscles

1. Intertransversarii

2. Interspinous

3. Multifidus

4. Rotators/Rotares/ Rotatores

Lateral Back muscle

Quadratus lumborum

Bilateral Contraction of Quadratus Lumborum

Acts as a stabilizer

Closed-kinematic chain Unilateral contraction of the Quadratus lumborum results in what motion?

Lateral flexion

Open-kinematic chain Unilateral contraction of the Quadratus lumborum results in what motion?

Hip Hiking

Main trunk flexor

Rectus Abdominis

Action of Internal Oblique

Ipsilateral flexion; rotation on the ipsilateral side

Action of External Oblique

ipsilateral lateral flexion; contralateral rotation

Transverse abdominis action

Abdominal compression (stabilize the sacroiliac joints)

The vertebral column offers a surprising degree of _____________

flexibility and movement

The intervertebral discs, which are located between the vertebrae, act as _______

shock absorbers

Parts of the Neural Arch

Pedicles + posterior elements

T9 has no ___________

inferior demi facet

as a larger, wedge-shaped body that contributes to the lumbar lordosis (inward curve)

L5

2 Functions of IVD

1. Separate 2 vertebral bodies → Increasing available motion

2. Transmit load

Size of IVD is related to ___________ and ___________

amount of motion and the magnitude of the loads

IVD make up how much of the length of the spine?

20-33%

Disc thickness in the cervical region

3mm

Disc thickness in the lumbar region

9mm

Greater Disc Thickness : Vertebral Body height ratio leads to what?

Available ROM

Greatest Disc height ratio

Cervical → Lumbar → Thoracic

A healthy IVD typically has a ratio of _______

0.33 - 0.45

Part of the IVD that provides most of the shock absorbing properties

Nucleus Pulposus

Function of the Annulus Fibrosus

Limits expansion of the Nucleus pulposus

Function of the Cartilaginous endplates

Anchor the IVD and allow nutrient diffusion

The cartilaginous endplates in the IVD are composed of thin layers of _____ cartilage

hyaline

What type of joints are the Interbody Joints

Symphysis, cartilaginous joint

Anterior Longitudinal Ligaments start at ____ and ends at the _____

C2-Sacrum

Anterior Longitudinal Ligaments limits what movement

Limits Extension

The PLL is broad in the _________ regions and narrow in the ______ region

Broad - Cervical and Thoracic

Narrow - Lumbar

The PLL limits what movement?

Forward flexion

ligament between lamina; C2-Scarum

Ligamentum Flavum

The Ligamentum flavum is thin, broad, and long in _________

cervical and thoracic region

The ligamentum flavum is thickest in ________ region

lumbar

The ligamentum f

Connects Spinous processes of adjacent vertebra

Interspinous

The Interspinous ligaments limits what movement?

Forward flexion

Connects the tips of the spinous processes

Supraspinous ligament

Supraspinous ligaments extends from the ______ to ______

C7 → L3/L4

The Supraspinous ligament becomes ________ in the cervical region

Ligamentum Nuchae

The Intertransverse ligament limits what movement?

Contralateral lateral flexion