VII. lower cervical biomechanics (C3-C7) Flashcards
Vertebral bodies in the lower cervical spine are wider ____ (transversely/A-P)
transversely
Articular facets of the lower cervical spine are at what angle with the horizontal plane?
45 degrees
Describe the articular surfaces of the Z-joints in the lower cervical spine?
nearly flat with some variation
What is the function of uncovertebral joints (joints of Luschka) in the lower cervical spine?
aid in guiding lateral flexion affect coupled rotation
What is the approximate thickness of IVDs in the lower cervical spine?
3mm
What is the disc to body ratio in the lower cervical spine?
2:5
IVDs in the lower cervical spine are thickest where?
anteriorly
Where is the nucleus of the IVDs located in the lower cervical spine?
slightly posterior to center
What is the segmental range of motion for combined flexion/extension in the lower cervical spine?
approximately 15 degrees per segment
Where is the segmental range of motion for combined flexion/extension in the lower cervical spine greatest?
in mid cervicals with approximately 20 degrees
Where is the segmental range of motion for combined flexion/extension in the lower cervical spine lowest?
at C2-C3 and C7-T1 with 10 degrees
What is the IAR for extension/flexion in the lower cervical spine?
anterior portion of the subadjacent vertebrae
What is the kinematic pattern of motion for extension/flexion in the lower cervical spine?
predominantly angular movement in the sagittal plane with couple sagittal plane translation
flexion = +θ x with +z
extension -θ x with -z
During flexion in the lower cervical spine, anterior disc is ____ (distracted/compressed) and the posterior disc is ____ (distracted/compressed)
compressed : distracted
During extension in the lower cervical spine, anterior disc is ____ (distracted/compressed) and the posterior disc is ____ (distracted/compressed)
distracted : compressed
During flexion in the lower cervical spine, facets ____ (separate/approximate)
separate
During extension in the lower cervical spine, facets ____ (separate/approximate)
approximate
What is the segmental range of motion for lateral flexion of the lower cervical spine?
averages 7-8 degrees to each side
The segmental range of motion for lateral flexion of the lower cervical spine decreases in which direction?
caudal
What is the IAR for lateral flexion of the lower cervical spine?
debated
What is the kinematic pattern of motion for lateral flexion in the lower cervical spine?
lateral bending couples with ipsilateral axial rotation
*degree of coupled rotation decreases from cephalad to caudad
During lateral flexion of the lower cervical spine, lateral disc wedging and ____ (distraction/approximation) on the side of lateral flexion and ____ (distraction/approximation) on the opposite side
approximation : distraction
What is the segmental range of motion for rotation of the lower cervical spine?
averages 5 degrees to each side and nearly uniform from C3-C7
What is the IAR for rotation in the lower cervical spine?
contralateral subadjacent vertebral body
What is the kinematic pattern of motion for rotation in the lower cervical spine?
predominantly axial rotation mildly coupled with ipsilateral lateral flexion
i.e vertebral bodies laterally flex to the side of rotation
During rotation in the lower cervical spine, on the side of rotation the inferior facet rides ____ (up/down) and ____ (laterally/medially)
down : medially
During rotation in the lower cervical spine, on the opposite side of rotation the inferior facet rides ____ (up/down) and ____ (laterally/medially)
up : laterally
What posterior muscles contribute to kinetics in the lower cervical spine?
splenius capitis
splenius cervicis
semispinalis capitis
semispinalis cervicis
longissimus capitis
longissimus cervicis
What anterior muscles contribute to kinetics in the lower cervical spine?
scalenes
longus colli
longus capitis
SCM
What segmental muscles contribute to kinetics in the lower cervical spine?
multifidus
rotatores
intertransversarii
Flexion of the lower cervical spine is initiated by what muscles?
concentric activity of anterior cervical muscles
Flexion of the lower cervical spine is guided by what muscles?
eccentric activity of the semispinalis, longissimus and splenius
Flexion of the lower cervical spine is limited by what?
eccentric activity of posterior neck muscles
elastic limits of myofascial tissue
Nuchal, flaval and PLL
joint capsule
posterior IVD distraction
anterior IVD compression
chin hitting chest
Extension of the lower cervical spine is initiated by what muscles?
concentric activity of posterior cervical muscles
Extension of the lower cervical spine is guided by what muscles?
eccentric activity of SCM, scalenes, longus colli and longus capitis
Extension of the lower cervical spine is limited by what?
eccentric activity of anterior neck muscles
elastic limits of myofascial tissue
anterior IVD distraction
posterior IVD compression
ALL
joint capsule
facet joint approximation
Lateral flexion of the lower cervical spine is initiated by what muscles?
ipsilateral concentric contraction of lateral flexors
Lateral flexion of the lower cervical spine is guided by what muscles?
contralateral eccentric contraction of lateral flexors
Lateral flexion of the lower cervical spine is limited by what?
contralateral eccentric muscle activity
elastic limits of myofascial tissue
tension of contralateral joint capsule, periarticular and flaval ligaments
contralateral IVD distraction
ipsilateral IVD compression
ipsilateral articular pillars/facet joint approximation
Rotation of the lower cervical spine is initiated by what muscles?
concentric contraction of ipsilateral splenius capitis and cervicis, longissimus cervicis
concentric contraction of contralateral semispinalis cervicis and SCM
Rotation of the lower cervical spine is guided by what muscles?
concentric contraction of contralateral splenius capitis and cervicis, longissimus cervicis
concentric contraction of ipsilateral semispinalis cervicis and SCM
Rotation of the lower cervical spine is limited by what?
capsular and periarticular ligaments
segmental muscles
facet joints
What are the possible views to obtain by X-ray of the lower cervical spine?
AP cervical
lateral cervical
obliques
flexion/extension studies
