CEA Manual Material Handling 2 — Questions and Answers
Question 1: Which NIOSH equation variable accounts for the horizontal distance of the load from the worker's body at the origin of lift?
- Vertical multiplier (VM)
- Horizontal multiplier (HM) (Correct answer)
- Distance multiplier (DM)
- Coupling multiplier (CM)
Correct answer: Horizontal multiplier (HM)
The horizontal multiplier (HM) penalizes lifts where the load is far from the body, reducing the recommended weight limit.
Question 2: A worker lifts a box from floor to shelf height repeatedly. Which body region is at highest risk for musculoskeletal injury during this task?
- Cervical spine
- Lumbar spine (Correct answer)
- Wrist and hand
- Shoulder rotator cuff
Correct answer: Lumbar spine
Floor-to-shelf lifts impose maximum compressive and shear forces on lumbar discs, making the lower back the highest-risk region.
Question 3: What does the Lifting Index (LI) value of 1.0 indicate under the NIOSH lifting equation?
- The task is extremely hazardous
- The task is at the upper boundary of acceptable risk (Correct answer)
- The load exceeds occupational limits for all workers
- The task requires engineering controls immediately
Correct answer: The task is at the upper boundary of acceptable risk
An LI of 1.0 means the actual load equals the recommended weight limit, representing the boundary of nominal risk.
Question 4: Which pushing/pulling metric is considered the most reliable predictor of musculoskeletal disorder risk?
- Peak force at initiation (Correct answer)
- Sustained push force
- Cart weight
- Walking speed during push
Correct answer: Peak force at initiation
Peak initial force required to break static friction is the best predictor because it represents maximum musculoskeletal loading during push/pull tasks.
Question 5: According to ergonomics guidelines, what is the recommended maximum weight for a one-handed carry by an average male worker under ideal conditions?
- 10 lbs
- 15 lbs
- 22 lbs (Correct answer)
- 35 lbs
Correct answer: 22 lbs
22 lbs (10 kg) is the commonly cited guideline for one-handed carrying to minimize asymmetric spinal loading.
Question 6: When evaluating a team lift, how should the team lifting capacity generally be calculated compared to individual capacities?
- Sum of all individual capacities
- 80% of the sum of individual capacities (Correct answer)
- Capacity of the weakest team member only
- 150% of the strongest member's capacity
Correct answer: 80% of the sum of individual capacities
Team lifting efficiency is approximately 80% of the summed individual capacities due to coordination and load-sharing inefficiencies.
Question 7: Which flooring characteristic most significantly increases the physical demand of pushing a loaded cart?
- Floor color
- High coefficient of friction between floor and cart wheels (Correct answer)
- Floor temperature
- Floor reflectivity
Correct answer: High coefficient of friction between floor and cart wheels
High rolling resistance from rough or sticky flooring dramatically increases the push force required, raising musculoskeletal strain.
CEA Manual Material Handling 2
Which NIOSH equation variable accounts for the horizontal distance of the load from the worker's body at the origin of lift?