Lifting

Question 1

What is Mechanical Advantage?

Answer 1

When the MA>RA - Moment arm (force) is longer than resistance arm (load)

Question 2

What does it mean when MA

Answer 2

Mechanical disadvantage, the moment arm (force) is shorter than the resistance arm (load)

Question 3

How do we reduce the amount of force required of the back extensor muscles during lifting?

Answer 3

Reduce the length of the resistance arm and increase the length of the moment arm

Question 4

How do we create mechanical advantage when lifting?

Answer 4

Put the load as near to the fulcrum as possible and keep the back straight and reduce weight of load

Question 5

What is combined loading?

Answer 5

Actual stresses experienced by discs and other musculoskeletal joints during ‘real world’ activities in the workplace

Question 6

What can cause combined loading?

Answer 6

weight of various body segments, weight of objects being lifted or carried, push/pull forces, bending the back forwards/backwards/sideways, twisting motions of the back and the back muscles (erector spinae)

Question 7

What are the 2 types of lifting failure?

Answer 7

Traumatic acute failure and cumulative trauma failure

Question 8

What is stability?

Answer 8

• essential feature of all movement to keep the body in stable equilibrium.

Question 9

True or false - stability is greater when COG is higher?

Answer 9

False - it is greater when the COG is lower

Question 10

What is the base of support?

Answer 10

The distance between parallel feet when upright, the wider the feet, the more stable, the closer less stable

Question 11

Name 3 safe lifting techniques

Answer 11

1. load should be light as practical
2. load should be held as close to the body as possible
3. keep spine as close to neutral position as possible
4. fully use hips and knee extensors when lifting
5. minimise the vertical and horizontal distance the load must be lifted
6. Avoid twisting when lifting
7. lift as slowly and smoothly as conditions allow
8. Lift with moderately wide and slightly staggered support provided by the legs
9. When possible use the assistance of a mechanical device or additional people to lift something