CIEE Manual Material Handling Assessment 5 — Questions and Answers
Question 1: Which scenario would cause the asymmetric multiplier (AM) in the NIOSH lifting equation to equal 1.0?
- The lift involves a 90-degree trunk twist
- The lift is symmetric — the worker faces the load directly with no trunk rotation (Correct answer)
- The lift is performed with both hands at different heights
- The load weighs exactly 23 kg
Correct answer: The lift is symmetric — the worker faces the load directly with no trunk rotation
AM = 1 – (0.0032 × A), so when the asymmetry angle A = 0 degrees (symmetric lift), AM = 1.0, meaning no penalty is applied.
Question 2: An ergonomic assessment reveals workers are lifting 18 kg pallets from the floor repeatedly. Which administrative control would be LEAST effective as a standalone intervention?
- Implementing job rotation to reduce exposure duration per worker
- Providing back-safety training to workers on proper lifting technique (Correct answer)
- Reducing shift length from 10 to 8 hours
- Cross-training workers to share lifting tasks across more employees
Correct answer: Providing back-safety training to workers on proper lifting technique
Back safety training alone has limited effectiveness as an intervention because it does not change the physical demands or task design causing the hazard.
Question 3: When using the Revised Strain Index (RSI) to evaluate a manual material handling task, the tool is MOST appropriate for assessing risk of injury to which body region?
- Lumbar spine
- Distal upper extremity (hand, wrist, forearm) (Correct answer)
- Shoulder and rotator cuff
- Cervical spine
Correct answer: Distal upper extremity (hand, wrist, forearm)
The Revised Strain Index was developed specifically to predict distal upper extremity disorders, including carpal tunnel syndrome and tendinitis of the hand and wrist.
Question 4: During a MMH assessment, you observe that a worker's Lifting Index is 2.4 for a non-routine lift performed once per hour. The appropriate recommended action is to:
- Accept the task because non-routine lifts are exempt from NIOSH limits
- Re-engineer the task immediately as an LI above 2.0 indicates substantial injury risk for most workers (Correct answer)
- Monitor the worker for 90 days before intervening
- Issue a personal protective equipment kit and document the observation
Correct answer: Re-engineer the task immediately as an LI above 2.0 indicates substantial injury risk for most workers
An LI above 2.0 indicates a significantly elevated injury risk requiring prompt engineering controls to reduce the LI below 1.0.
Question 5: Which condition would lead an ergonomic evaluator to classify coupling as 'poor' under the NIOSH lifting equation criteria?
- The load has an ergonomic handle positioned at its center of gravity
- The worker must wrap fingers under the load because there are no handles or hand-holds (Correct answer)
- The load is in a rigid container with two side handles
- The load weighs under 10 kg and the surface is dry
Correct answer: The worker must wrap fingers under the load because there are no handles or hand-holds
Poor coupling is assigned when there are no handles and the worker must finger-wrap or support the load from below, resulting in a coupling multiplier (CM) of 0.90.
Question 6: The composite Lifting Index (CLI) extends the NIOSH equation to multi-task scenarios by:
- Averaging the LI values of all individual lifting tasks in a job
- Summing the frequency-adjusted lifting demand fractions across all tasks to produce a single exposure index (Correct answer)
- Selecting the single highest individual task LI as representative of the whole job
- Multiplying LI values from each task together to obtain compounded risk
Correct answer: Summing the frequency-adjusted lifting demand fractions across all tasks to produce a single exposure index
The CLI sums the incremental frequency-adjusted demand fractions for each subtask, sorted from highest to lowest LI, to reflect cumulative spinal loading across multiple lifting tasks.
Question 7: Which of the following changes to a manual handling task would improve the frequency multiplier (FM) WITHOUT reducing the number of lifts completed per shift?
- Decreasing the weight of individual loads by 20%
- Adding a scheduled rest break that reduces continuous lifting duration below the NIOSH duration threshold (Correct answer)
- Raising the origin height by 30 cm
- Decreasing asymmetry angle from 45 to 0 degrees
Correct answer: Adding a scheduled rest break that reduces continuous lifting duration below the NIOSH duration threshold
FM is determined by both lifts-per-minute and task duration category; adding a rest break can shift the task into a shorter duration category, improving FM without changing the lift rate.
CIEE Manual Material Handling Assessment 5
Which scenario would cause the asymmetric multiplier (AM) in the NIOSH lifting equation to equal 1.0?