CPE Workplace Design & Modifications 2 — Questions and Answers
Question 1: When designing a sit-stand workstation, what is the primary ergonomic criterion for setting the correct standing work surface height?
- Elbow height with arms relaxed at the sides (Correct answer)
- Shoulder height of the tallest user
- Mid-chest height to reduce reach distance
- Wrist height when arms are extended forward
Correct answer: Elbow height with arms relaxed at the sides
Standing work surface height should align with elbow height (arms relaxed) to minimize shoulder elevation and static muscle loading.
Question 2: A manufacturing plant wants to reduce musculoskeletal injuries at a assembly line. Which modification BEST addresses cumulative trauma from repetitive wrist flexion?
- Rotating workers to different tasks every two hours (Correct answer)
- Installing padded wrist rests at every station
- Raising conveyor height by 15 cm
- Increasing line speed to reduce total daily exposure
Correct answer: Rotating workers to different tasks every two hours
Job rotation distributes cumulative loading across different muscle groups, directly reducing the dose of repetitive wrist flexion for each worker.
Question 3: Under the Americans with Disabilities Act (ADA), what is the maximum height for forward-reach objects at an accessible workstation?
- 48 inches (122 cm) (Correct answer)
- 54 inches (137 cm)
- 60 inches (152 cm)
- 36 inches (91 cm)
Correct answer: 48 inches (122 cm)
ADA standards specify a maximum forward reach of 48 inches above the floor for accessible workstation elements.
Question 4: An ergonomist is evaluating a control room where operators monitor multiple screens for 8-hour shifts. Which seating feature is MOST critical for this task?
- Adjustable lumbar support and seat pan depth (Correct answer)
- High-back fixed lumbar position
- Saddle-style seat to improve posture
- Forward-tilting seat pan to increase alertness
Correct answer: Adjustable lumbar support and seat pan depth
Adjustable lumbar support and seat pan depth accommodate diverse body sizes and allow dynamic posture changes during long monitoring shifts.
Question 5: Which workstation dimension is MOST directly affected by the 5th-percentile female anthropometric data when designing for maximum reach?
- Maximum horizontal reach distance (Correct answer)
- Minimum leg clearance depth
- Optimum eye height for screen placement
- Preferred keyboard height
Correct answer: Maximum horizontal reach distance
Designing maximum reach for the 5th-percentile female ensures that the smallest users can reach controls without overextension.
Question 6: A warehouse ergonomics audit reveals workers frequently lift boxes from floor level to overhead shelves. Which intervention should be prioritized FIRST in the hierarchy of controls?
- Install adjustable-height pallet lifts to eliminate floor-level lifts (Correct answer)
- Provide back belts to all lifting workers
- Train workers in proper lifting technique
- Assign lighter boxes to smaller workers
Correct answer: Install adjustable-height pallet lifts to eliminate floor-level lifts
Engineering controls such as pallet lifts eliminate the hazardous posture at the source, ranking above administrative or PPE solutions.
Question 7: When modifying a hand-tool grip for a precision assembly task, which grip diameter range minimizes gripping force for MOST adult workers?
- 30–40 mm (1.2–1.6 in) (Correct answer)
- 10–15 mm (0.4–0.6 in)
- 60–70 mm (2.4–2.8 in)
- 50–55 mm (2.0–2.2 in)
Correct answer: 30–40 mm (1.2–1.6 in)
A grip diameter of 30–40 mm optimizes the mechanical advantage of finger flexors, reducing required grip force for precision tasks.
CPE Workplace Design & Modifications 2
When designing a sit-stand workstation, what is the primary ergonomic criterion for setting the correct standing work surface height?