Motion Segments Flashcards
What is a motion segment?
The functional unit of the vertebral column since it allows movement
What does a vertebral motion segment consist of?
Two adjacent vertebrae
Soft tissues between them
What is the reference for definition of motion Segments?
Hall, 2014
What is the function of the vertebral bodies in the motion segment?
Allow body to support its weight
Stable attachment for IVDs, ligaments and muscles
(Duran et al., 2017)
What movements of the vertebral column do the annulus fibres of the IVDs resist? (Reference?)
Flexion
Extension
Torsion
(McNah and McCulloch, 1990)
What percentage of the nucleus pulposus is water?
90%
What are the other components of the nucleus pulposus apart from water? (Reference?)
Proteoglycans
Collagen
Glycosaminoglycans
(Palastanga et al., 2012)
What are the five steps involved in the development of the IV discs?
- Paraxial somites gather around notochord
- Pericordial condensation of sclerotome
- Metameric patterning of disc and vertebral bodies
- Involution of notochord
- Establishment of annulus fibrosus lamellar structure
How does the notochord form? (Reference?)
Epiblast cells invaginating at Hensen’s node and filling the mesoblastic space
(Colombier et al., 2014)
What does the nucleus pulposus derive from? (Reference?)
Notochord
Martinez et al., 2017
What does the annulus fibrosus derive from? (Reference?)
Sclerotome
Colombier et al., 2014
When does the notochord tend to be completely degraded and where can it remain up to 10 years of age? (Reference?)
Usually gone by 4-5 years of age
Can remain in IV disc up to 10 years
(Ashley et al., 2016)
What applies tension to IV discs?
Ligaments
What applies external loads to the IV discs?
Things we carry
Body weight and its compression on the vertebral column and IV discs is a risk factor for what?
(Reference?)
Lower back pain
Shiraz et al., 2015