Spine Flashcards
what is vertebral facet orientation in the cervical region?
horizontal transitioning to frontal
what structure allows for the majority (50%) of cervical rotation? why?
Atlanto-axial joint
horizontal facets allow for horizontal movement (rotation)
what is the most common movement in the lower c spine, why?
lateral flexion
due to facet orientation transitioning from horizontal to frontal plane
how is the lower c spine angled?
45 degrees
what is the primary movement of the thoracic spine?
although the facets allow for side bending, the thoracic column’s primary function is stability
how do the vertebral facet joints change from the beginning to the end of the thoracic column?
45 degrees to full frontal
what is the facet orientation in the lumbar spine?
nearly sagittal to promote flexion/extension
what is the most mobile area of the spine?
c spine
which plane is the most mobile throughout the column?
sagittal plane
where is the most movement in the sagittal plane? why?
thoracic spine - even though the facets tell us otherwise!
this is because the t-spine is already curved in the sagittal plane
what model does Julie use for the intervertebral discs?
multiple nylon stockings around pudding
what is the major component of the discs?
water!
what does the nucleus pulposus do?
absorbs and dissapates shock
what does the annulus fibrosus do?
retains the nucleus pulposus
what is the structure of the annulus fibrosus?
collagen fibers arranged in sheets (lamellae)
where is the annulus fibrosus the thickest?
anteriorly
what does the vertebral endplate do?
caps and binds the annulus fibrosus
what force is implicated in intervertebral discs?
hydrostatic pressure from the nucleus pulposus increases tension in the annulus fibrosus
how is pressure distrubuted in the annulus fibrosus in an intact system?
equally and evenly
are the vertebral discs a closed system? why or why not.
no, there are diurnal fluctuations in water content and the discs rehydrate at night
Around what age does the nucleus pulposus begin to dehydrate
35-40
in which 3 positions are disc loading pressures minimized?
supine, sidelying, and semi-fowler
why can’t disc loading pressure realistically be eliminated completely?
ligamentous pressure applies slight loading pressure independent of positioning
when in disc loading pressure the greatest? (3 from most to least pressure)
- bent over load lifting
- hips/knees bent load lifting
- neutral posture load carrying
