Motion Segments

Question 1

A motion segment is the smallest physiological motion unit of the spine to exhibit the biomechanical characteristics applicable to the whole spine. This consists of 2 adjacent vertebral bodies and their associated 3 joint complex as well as the soft tissues

Answer 1

Butt et al., (2015)

Question 2

VB is formed of trabecular bone which is prone to osteoporosis in elderly individuals, this equates a loss of density in the bone which leads to a decrease in load taken by the anterior spine and an increase in load taken by the posterior elements

Answer 2

Pitzen et al., (2001)

Question 3

Drawing of the IVD

Answer 3

Colombier et al., (2013)

Question 4

IVDs anchor the vertebrae together, allow for movement and in the L region distribute pressure from the entire trunk

Answer 4

Colombier et al., (2013)

Question 5

In humans signs of IVD degeneration seen as early as skeletal maturity when notochordal cells responsible for homeostasis of the IVD are lost

Answer 5

Colombier et al., (2013)

Question 6

Aging of the IVD- loss of proteoglycan from the NP and loss of disc height, NP becomes fibrous and loses its ability to deform under stress. in AF matrix degrades and collagen fibres become thinner and may crack or bulge

Answer 6

Colombier et al., (2013)

Question 7

NP has a high water content which allows it to demonstrate hydrostatic pressure under load which is transferred to the AF

Answer 7

Newell et al., (2017)

Question 8

AF is made up of concentric layers of type I collagen fibres which allow it to develop tensile hoop stress due to pressure from the NP

Answer 8

Newell et al., (2017)

Question 9

Generally resistance within the motion segment is greater in axial rotation then extension then lateral flexion and finally least resistance to flexion

Answer 9

Newell et al., (2017)

Question 10

IVD degeneration likely multifactorial and a combination of biomechanical wear and tear and disturbance of cellular activity

Answer 10

Vergroesen et al., (2015)

Question 11

For lumbar disc prolapse discectomy for selected pts provides faster relief in the acute setting than conservative management

Answer 11

Gibson and Waddell, (2008)

Question 12

90% of acute attacks of disc prolapse settle with conservative management
Is an uncommon cause of back pain but common cause of nerve root pain

Answer 12

Gibson and Waddell, (2008)