The Back

Question 1

According to the National Institute for Occupational Safety and Health (NIOSH), what percentage of lower back pain is due to overexertion?

Answer 1

60%

Question 2

According to NIOSH, (1981), if patients are away from work for a long time, how many return to the same job?

Answer 2

Less than one third

Question 3

What fraction of overexertion injuries involved lifting and pushing/pulling, according to NIOSH, (1981)?

Answer 3

2/3 involve lifting

1/5 involve pushing/pulling

Question 4

What fraction of all exported Occupational injuries are caused by overexertion?

Answer 4

1/4

Question 5

What is the recommended weight limit?

Answer 5

23kg

Question 6

According to the Health and Safety Executive (HSE), (2016) how many work related illnesses are musculoskeletal disorders?

Answer 6

539,000

Question 7

What are the main workplace causes, according to GPs, of musculoskeletal disorder exacerbations?

Answer 7

He at lifting
Keyboard work
Manipulating materials

Question 8

What are the commonest occupations related to musculoskeletal disorders?

Answer 8

Specialised construction
Agriculture
Human health and residential care

Question 9

What are the most common causes of lower back pain musculoskeletal disorders?

Answer 9

Manual handling, lifting and carrying (53%)

Question 10

What are the other common causes of lower back pain musculoskeletal disorders?

Answer 10

Awkward/Tiring positions
Workplace accidents
Keyboard use/RSIs

Question 11

What intrinsic muscles stabilise the spine?

Answer 11

Rotatores
Multifidus
Semispinalis capitis/thoracis

Question 12

What is the main function of erector spinae muscles? What is the predominant fibre type?

Answer 12

Extension

Type I fibres -> Postural

Question 13

How does the spinal structure resist load?

Answer 13

Relatively stable
Can remain erect
Strong ligaments
Curvatures

Question 14

What is the motion segment of the vertebral column?

Answer 14

Inferior half of superior vertebra
IV disc
Superior half of inferior vertebra

Question 15

What are the passive and active parts of a vertebral motion segment?

Answer 15

Passive = Bone
Active = Collagen fibres in anterior IV disc under increased tension during extension

Question 16

How do the extensor muscles result in a compressive load on the spine?

Answer 16

In normal upright posture, centre of gravity is anterior to vertebrae
Spine therefore has a moment acting on it
This is counteracted by extensors

Question 17

How does Flexion increased the force needed to be generated by extensors?

Answer 17

Flexion moves centre of gravity forward so moment is greater

Therefore more extensor force is needed to maintain posture

Question 18

What forces does axial loading subject the vertebrae to? Where are these forces greatest and why?

Answer 18

Compressive force (Fc)
Shear force (Fs)
Lumbar region - Vertebra above tend to slide forward on vertebra below

Question 19

In what position is the load on L3/L4 disc markedly reduced?

Answer 19

Supine

Question 20

What are the ranges of movement in the cervical spine?

Answer 20

Flexion = 25 degrees
Extension = 85 degrees
Lateral flexion = 40 degrees
Rotation = 50 degrees

Question 21

What are the ranges of motion in the thoracic spine?

Answer 21

Flexion = 30-40 degrees
Extension = 20-30 degrees
Lateral flexion = 20-25 degrees
Rotation = 35 degrees

Question 22

What are the ranges of motion in the lumbar spine?

Answer 22

Flexion = 30 degrees
Extension = 55 degrees
Lateral flexion = 20-30 degrees
Rotation = 1-5 degrees