6.5 Lower Back Pain

Question 1

The load carried by the upper body must be transferred via the spine to the lower limbs:
• ____________ is the main weightbearing part of the spine
• Bigger vertebral bodies with greater surface area for transferring load (vs small vertebral bodies in the cervical spine → cervical spine’s primary function is ________ rather than stability and weight transfer)

Answer 1

Lumbar spine;

mobility

Question 2

The intervertebral discs are made of the _________ (filled with water) surrounded by the ______________ (rings of annular fibres):
• Fibres of the annulus fibrosus are alternately orientated → _______ structure (helps with load bearing and movement)
• The ___________ are not shock absorbers

The nucleus pulposus is a ball of fluid that can be compressed but not changed in shape:
• Compressing the nucleus pulposus causes it to press out against the annular rings (which exert an opposite force to maintain the shape) → rigid structure
• In the morning: nucleus is very hydrated → very tight
• During __________: water content changes → becomes more compliant

Answer 2

inner nucleus pulposus;

annulus fibrosus;

grid;

intervertebral discs;

standing and other loadbearing activities

Question 3

Cervical vertebrae

• Small-sized
• Transverse processes are ____________
• Spinous process is ___________
• Function: ____________

Answer 3

not very clearly demarcated;

much thinner and has a bifid structure (less stability);

mobility of the head and neck

Question 4

Thoracic vertebrae

• Medium-sized
• Transverse processes facet joints restrict ____________
• Spinous process project inferiorly to prevent _____________
• Function: ____________

Answer 4

rotation;

flexion and extension;

support thoracic cage (housing vital organs)

Question 5

Lumbar vertebrae

• Big and kidney shaped
• Transverse processes facet joints prevent spine from _________________
• Articular processes are much _____________ → points of attachment for muscles (provide stability)
• Function: ____________

Answer 5

over-rotation, lateral bending or side flexion;

stouter and solid;

distribution of load (but poor mobility)

Question 6

Shattered vertebrae: people who jump from a height tend to shatter their vertebrae rather than damage their intervertebral discs
• Due to the ______________ going around it
• However, the structure of the vertebral body also tries to resist load due to the bone structure and the trabeculae within the vertebral body

Answer 6

nucleus pulposus and the annular fibres

Question 7

What is the mechanics of bending forwards/ backwards

Answer 7

Nucleus pulposus is pushed in the opposite direction, but the restraint offered by the annulus fibrosus causes the displacement to only be marginal

Question 8

What is the mechanics of compression/ stretching?

Answer 8

Diagonal structures of the annulus fibrosus prevents any displacement during compression and stretching

Question 9

What is the mechanics of compression/ stretching?

Answer 9

Signs of vulnerability as the diagonal layers of the annulus fibrosus (from alternately orientated fibres) do not offer as much restraint to this type of motion

Question 10

What injury is likely to occur due to rotation and lateral flexion?

Answer 10

Intervertebral disc prolapse

Question 11

Intervertebral disc prolapse occurs via a series of events following degeneration from repeated abuse → _____________(due to activities like bad posture, heavy lifting):

1. All laminae fail: microtears start as a crack in the _____________ which spreads to other layers, which forms a tract going to the outermost margin in the __________
2. Not all laminae fail: weakness in the vertebral body causes prolapse into the vertebral end plate then into the vertebral body (tends to prolapse ______________ due to the rotational component involved in the failure of the disc)

Answer 11

microtears/fissures;

lamina;

annulus fibrosus;

posterolaterally

Question 12

As the disc prolapses, the fluid in the nucleus pulposus starts to leak into the spinal canal, creating a chemical inflammation in the whole region, including around the nerve:
• Chemical inflammation (from fluid leakage) irritates the _______________ → shooting pain
• Fluid presses onto the nerve root → mechanical irritation → _____________ pain
• Degree of the pain and inflammation is dependent on the amount of fluid that has leaked as well as the anatomy of the person (amount of room in the root canals)
• Any compression in the ___________ leads to radiating pain in the legs

Answer 12

nerve root;

shooting;

lumbar spine

Question 13

A more severe nerve root compression causes more severe symptoms (apart from pain):
• Initially: patient complains about ______, ____, ________
• Prolonged condition: __________ (due to disuse) and ____________ (due to disturbance in nerve supply to the muscle) → reflected in the patient’s posture
o Patient adjusts posture to try and open up the nerve canal to relieve the pressure → _____________

Answer 13

numbness, weakness and pain;

muscular atrophy; loss of reflexes;

scoliosis (abnormal lateral curvature of the spine)

Question 14

What are the clinical features of herniated lumbar nucleus pulposus at the L4- L5 disc (5th lumbar nerve root)

• Pain over sacro-iliac joint, hip, lateral thigh and leg
• Numbness at ______________
• Weakness in dorsiflexion of great toe and foot, difficulty walking on heels, ___________ may occur
• ________________ diminished or absent

Answer 14

lateral leg, first 3 toes;

foot drop

internal hamstring reflex

Question 15

What are the clinical features of herniated lumbar nucleus pulposus at the L5- S1 disc (1st sacral nerve root)

• Pain over ______________
• Numbness at ______________
• Weakness in dorsiflexion of great toe and foot, difficulty walking on toes
• ________________ diminished or absent

Answer 15

sacro-iliac joint, hip, posterolateral thigh and leg to heel;

Back of calf, lateral heel, foot to toe;

ankle jerk

Question 16

Cauda equina syndrome is an acute, emergency condition as the longer the cauda equina syndrome occurs without management, the less function they will have after management:

• Due to the disc material compressing the ________________ and compromises the function of the spinal cord
• Signs: urinary retention, incontinence, sexual dysfunction, saddle anaesthesia (loss of sensation to _______________), leg pain & weakness
• Management: surgical via ______________

Answer 16

spinal cord (lumbar plexus or cauda equina);

buttocks, perineum and inner surfaces of thigh;

decompression (e.g. laminectomy)

Question 17

Degenerative disc disease is another common injury related to back pain, which occurs due to _________________:

• Common in people who do a lot of manual labour, sports or loading
• Genetic factors may also contribute to the degeneration of the disc
• In degenerative disc disease, the disc dries out (______________ is no longer fluid-filled):
• Occurs in only a single disc in young people (under 23 years old), but occurs in multiple discs in older people (affecting the lower discs more)
• Seen as a _______________ on radiographs

With the loss of hydration, the disc is no longer as firm and cannot resist load as well:

• Adaptive mechanism: body shifts the load to the vertebral body and facet joints → vertebral body develops _______________ (due to abnormal loading) and damage to the facet joints causes _______________
• Osteophyte formation and thickening (due to inflammation) compromises the __________________, which can result in leg pain or spinal stenosis

Answer 17

prolonged abnormal movement and loading;

nucleus pulposus;

blacked-out disc;

osteophytes;

osteoarthritis;

diameter of the lateral root canal

Question 18

Central Spinal Stenosis

• Tends to occur in people aged __________ years (compared to disc prolapse which tends to occur in people aged 30 – 40 years)
• less common
• Related to ____________

Answer 18

60 – 80’

poor nutrition → poor development of the vertebrae

Question 19

Central Spinal Stenosis

• Tends to occur in people aged 60- 80 years (compared to disc prolapse which tends to occur in people aged ________ years)
• more common
• May be due to ____________________

Answer 19

30 – 40

various causes (including degenerative disc disease)

Question 20

What are the characteristics of lordoisis?

Answer 20

Locks their knees and puts additional load on the lumbar spine:
- Present with a straight upright spine as they contract their muscles to make their pelvis and lumbar spine rigid

Question 21

What are the characteristics of kyphosis?

Answer 21

Presents with an excessive posterior curvature of the thoracic spine
- Can be caused by diseases such as osteoporosis