CIEE Manual Material Handling Assessment 4 — Questions and Answers
Question 1: Which psychophysical method asks workers to adjust load weight or force until they reach their maximum acceptable level for a given task?
- Borg CR-10 scale assessment
- Maximum Acceptable Weight of Lift (MAWL) method (Correct answer)
- RULA postural analysis
- OWAS sampling technique
Correct answer: Maximum Acceptable Weight of Lift (MAWL) method
The Maximum Acceptable Weight of Lift (MAWL) psychophysical method asks subjects to self-regulate load weight until reaching the heaviest they can handle without overexertion.
Question 2: When assessing a lowering task using the NIOSH lifting equation, the evaluator should:
- Ignore the lowering phase because only lifting creates lumbar injury risk
- Calculate the RWL at the origin (top) and destination (bottom) and use the more restrictive value (Correct answer)
- Use only the destination RWL because lowering loads are always lighter
- Apply a fixed 20% reduction to the standard RWL for all lowering tasks
Correct answer: Calculate the RWL at the origin (top) and destination (bottom) and use the more restrictive value
Both origin and destination RWLs must be computed for a lowering task, and the lower (more restrictive) value governs task acceptability.
Question 3: A job requires lifting 10 kg at a frequency of 12 lifts per minute for 8 hours. According to the NIOSH frequency multiplier (FM) table, what FM value applies?
- FM = 1.00
- FM = 0.00 (Correct answer)
- FM = 0.45
- FM = 0.75
Correct answer: FM = 0.00
At 12 lifts/min over an 8-hour duration, the FM value drops to 0.00, meaning the task essentially exceeds physiological capacity regardless of other parameters.
Question 4: Which leading ergonomic indicator would most suggest unacceptable MMH risk BEFORE a musculoskeletal injury occurs?
- Increasing workers' compensation claim costs
- Workers reporting perceived exertion ratings above 13 on the Borg RPE scale during routine tasks (Correct answer)
- Post-incident OSHA 300 log entries for the job
- Medical restriction rates over the past fiscal year
Correct answer: Workers reporting perceived exertion ratings above 13 on the Borg RPE scale during routine tasks
Borg RPE scores consistently above 13 (somewhat hard) during routine tasks signal physiological strain and serve as a leading indicator before injuries are recorded.
Question 5: Which ergonomic tool is specifically designed to assess whole-body vibration exposure during manual material handling tasks involving powered industrial trucks?
- REBA worksheet
- ISO 2631-1 standard measurement protocol (Correct answer)
- OWAS observation method
- NIOSH lifting equation
Correct answer: ISO 2631-1 standard measurement protocol
ISO 2631-1 provides the standardized methodology for measuring and evaluating whole-body vibration (WBV) exposure in workers operating vehicles like forklifts.
Question 6: In the context of MMH risk assessment, the 'zone of convenient reach' is best described as:
- The area within arm's reach at or above shoulder height
- The region in front of the body between knuckle and shoulder height and within arm's reach (Correct answer)
- The area directly overhead accessible by the dominant hand
- Any location reachable without moving the feet
Correct answer: The region in front of the body between knuckle and shoulder height and within arm's reach
The zone of convenient reach encompasses the area in front of the body between knuckle and shoulder height where biomechanical stress is minimized during handling tasks.
Question 7: Which anthropometric measurement is most critical when designing a workstation to accommodate the 5th to 95th percentile range of workers for a pushing task?
- Seated knee height
- Standing elbow height (Correct answer)
- Biacromial shoulder breadth
- Functional leg length
Correct answer: Standing elbow height
Standing elbow height determines the optimal handle height for push/pull tasks, and designing for the 5th–95th percentile range of elbow heights accommodates most workers.
CIEE Manual Material Handling Assessment 4
Which psychophysical method asks workers to adjust load weight or force until they reach their maximum acceptable level for a given task?