Podcast
Questions and Answers
What primarily limits axial rotation when the spine is flexed?
What primarily limits axial rotation when the spine is flexed?
Which vertebral level demonstrates the largest lateral flexion range of motion and axial rotation?
Which vertebral level demonstrates the largest lateral flexion range of motion and axial rotation?
What is the main kinematic phenomenon described as spinal coupling?
What is the main kinematic phenomenon described as spinal coupling?
What is the kinematic relationship defined by lumbosacral rhythm?
What is the kinematic relationship defined by lumbosacral rhythm?
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Which structure largely shares the load in axial compression of the lumbar region?
Which structure largely shares the load in axial compression of the lumbar region?
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What helps reduce the amount of flexibility required in the lumbar region during motion integration?
What helps reduce the amount of flexibility required in the lumbar region during motion integration?
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What type of joints are Zygapophyseal articulations?
What type of joints are Zygapophyseal articulations?
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What happens to the lumbar lordosis during lumbar extension?
What happens to the lumbar lordosis during lumbar extension?
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Which ligament in the lumbar region limits extension?
Which ligament in the lumbar region limits extension?
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What increases with an increase in the lumbosacral angle?
What increases with an increase in the lumbosacral angle?
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What happens to the diameter of the intervertebral foramina during lumbar extension?
What happens to the diameter of the intervertebral foramina during lumbar extension?
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What is the main function of the Supraspinous ligament in the lumbar region?
What is the main function of the Supraspinous ligament in the lumbar region?
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In spinal rotation, what happens to the ipsilateral facet joints?
In spinal rotation, what happens to the ipsilateral facet joints?
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Which structure is inclined slightly anteriorly and inferiorly, forming the lumbosacral angle?
Which structure is inclined slightly anteriorly and inferiorly, forming the lumbosacral angle?
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Which structure migrates slightly towards the convex side of a lateral bend?
Which structure migrates slightly towards the convex side of a lateral bend?
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What restricts spinal rotation mainly due to its shape and tension?
What restricts spinal rotation mainly due to its shape and tension?
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Which ligament replaces the Intertransverse ligaments in the lumbar area at L4?
Which ligament replaces the Intertransverse ligaments in the lumbar area at L4?
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What happens to the superior vertebra during lateral flexion?
What happens to the superior vertebra during lateral flexion?
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Study Notes
Interbody Joints
- Capable of translations and tilts in all directions
Zygapophyseal Articulation
- True synovial joints
- Fibroadipose meniscoid structures present
- Facet joint capsule restrains axial rotation
- Resistance to anterior shear
Lumbosacral Articulation
- Located between 5th lumbar vertebra and 1st sacral segment
- 1st sacral segment is inclined slightly anteriorly and inferiorly, forming an angle with the horizontal (lumbosacral angle)
- Increase in lumbosacral angle increases lumbar lordosis and shearing stress at the lumbosacral joint
Ligaments
- Supraspinous ligament: well developed only in the upper lumbar region, terminates at L4 or L3
- Intertransverse ligaments: not true ligaments in the lumbar area, replaced by the iliolumbar ligament at L4
- Interspinous ligament: has the least overall stiffness
- Anterior longitudinal ligament: strong and well developed in this region
- Posterior longitudinal ligament: thin ribbon in the lumbar region
- Ligamentum flavum: thickened in the lumbar region
- Iliolumbar ligaments: series of bands extending from the transverse processes of L4 and L5 to the iliac crests of the pelvis, with three bands (ventral, dorsal, and sacral)
Ligament Function
- Anterior longitudinal ligament: limits extension
- Posterior longitudinal ligament: limits forward flexion
- Ligamentum flavum: limits forward flexion
- Supraspinous ligament: limits forward flexion
- Interspinous ligaments: limit forward flexion
- Intertransverse ligaments: limit contralateral lateral flexion
- Iliolumbar ligament: resists anterior sliding of L5 and S1
Muscles of Lower Spine Region
- Serve roles of producing and controlling movement of the trunk
- Stabilizing the trunk for motion of the lower extremities
- Assist in attenuating extensive forces that affect this area
Posterior Muscles
- 3 layers: superficial, intermediate, and deep
Spinal Coupling
- Kinematic phenomenon in which movement of the spine in one plane is associated with an automatic movement in another plane
- Most consistent pattern involves an association between axial rotation and lateral flexion
Lumbo-Pelvic Rhythm
- Kinematic relationship between the lumbar spine and hip joints during sagittal plane movements
- Bending forward: lumbar flexion (40°) followed by anterior tilting of the pelvis at the hip joint (70°)
- Return to erect: posterior tilting at the pelvis at the hips followed by extension of the lumbar spine
Kinetics
- Forces that cause, arrest, or modify motion in a system: gravity, muscles, friction, and external resistance
Compression
- Lumbar region provides support for the weight of the upper part of the body in static and dynamic situations
- Lumbar region must withstand tremendous compressive loads produced by muscle contraction
- Lumbosacral loads in erect standing posture: 0.82 to 1.18 times body weight
- Lumbosacral loads during level walking: 1.41 to 2.07 times body weight
Interbody Joint Motion
- Lumbar extension: increases lumbar lordosis, posterior tilting, and gliding of superior vertebra
- Lumbar extension reduces the diameter of intervertebral foramina
- Fewer ligaments checks extension
- Nucleus pulposus displaces anteriorly
Lateral Flexion
- Superior vertebra laterally tilts, rotates, and translates over the vertebra below
- Annulus fibrosus is compressed on the concavity of the curve and stretched on the convex side
- Nucleus pulposus migrates slightly towards the convex side of the bend
Spinal Rotation
- Rotation causes movement of the vertebral arch in the opposite direction
- Ipsilateral facet joints go for gapping and contralateral facet joints for impaction
- Axial rotation is limited due to the shape of the zygapophyseal joints and restricted by tension created in the stretched capsule of the apophyseal joints and stretched fibers within the annulus fibrosus
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Description
Test your knowledge on the different types of spinal articulations, including interbody joints, zygapophyseal articulations, and lumbosacral articulations. Learn about the structures and functions of these joints in the spine.
