Spine Biomechanics Flashcards
Wolff’s Law
Bone that is not used is lost
Spinal motion segment
The functional unit of the spine
As kyphotic deformity increases, the center of gravity moves —– from the axis of the spine.
Farther
What are the components of a spinal motion segment?
- 2 adjacent vertebrae
- 2 facet joints
- IVD
- ligaments shared by the two vertebrae
Biphasic material
One that is composed of two dissimilar elements, such as bone
Why is understanding spine biomechanics valuable in working with surgeons and other customers?
Because biomechanics explain why certain areas are more prone to failure than others under certain conditions.
Explain why one vertebral fracture might result in additional fractures.
With increased kyphosis, the center of gravity moves farther away from the axis of the spine which may throw off a persons balance and will increase the anterior load on the vertebral body. This increased load may cause fractures in individuals with osteoporosis.
What are the “three columns” of the three-column theory of the spine?
Anterior
Middle
Posterior
Explain the ANTERIOR components of the “three-column theory”
- anterior longitudinal ligament
- cortical and cancellous bone of the anterior half of VB
- anterior portion of the annulus fibrosus
Explain the MIDDLE components of the “three-column theory”
- posterior half of the vertebral body
- posterior and longitudinal ligament
- posterior portion of the annulus fibrosus
Explain the POSTERIOR components of the “three-column theory”
- posterior elements of the vertebral arch including:
- Pedicles,
- ligaments related to vertebral arch
Compare linear and rotational motion
- linear motion occurs along a line, has only one direction and can be stopped by an equal opposite force
- rotational motion happens in a circle and is composed of several forces that act at different times
