CHST Ergonomics and Musculoskeletal Disorder (MSD) Prevention 2

Question 1

In the revised NIOSH Lifting Equation, what is the load constant used to calculate the Recommended Weight Limit (RWL)?

Accepted Answer

51 lb (23 kg)

Answer

The revised NIOSH equation starts from a 51 lb (23 kg) load constant, which the task multipliers then reduce.

Question 2

A NIOSH Lifting Index (LI) of 2.4 for a block-laying task indicates what?

Accepted Answer

The task carries elevated risk of lifting-related low back pain for many workers

Answer

LI is load weight divided by RWL, and values above 1.0 show increased risk, rising as LI goes up.

Question 3

Under the NIOSH Lifting Equation, what happens to the Horizontal Multiplier as a load is held farther from the body?

Accepted Answer

It decreases, lowering the RWL

Answer

HM = 10/H (inches), so a larger horizontal distance gives a smaller multiplier and a lower recommended weight.

Question 4

What vertical hand height at the start of a lift does the NIOSH equation treat as optimal (multiplier of 1.0)?

Accepted Answer

About 30 inches (75 cm) above the floor

Answer

The Vertical Multiplier equals 1.0 at roughly knuckle height of 30 in (75 cm) and drops above or below that.

Question 5

Which change would most improve the RWL for a laborer who twists 90 degrees to set pavers on a pallet?

Accepted Answer

Rearranging the layout so the worker faces the pallet without twisting

Answer

Getting rid of trunk twisting brings the Asymmetric Multiplier back toward 1.0 and raises the recommended weight limit.

CHST - Construction Health and Safety Technician Practice Test