CEA Workplace Ergonomic 3 — Questions and Answers
Question 1: Which anthropometric measure is most critical when setting seated workstation height for a diverse workforce?
- Standing height
- Popliteal height (Correct answer)
- Sitting eye height
- Shoulder breadth
Correct answer: Popliteal height
Popliteal height (back of knee to floor) determines optimal seat height to allow feet to rest flat and thighs to be roughly horizontal.
Question 2: A warehouse employee frequently lifts boxes from floor level. Which NIOSH lifting equation multiplier is MOST penalizing in this scenario?
- Frequency Multiplier (FM)
- Asymmetry Multiplier (AM)
- Vertical Multiplier (VM) (Correct answer)
- Coupling Multiplier (CM)
Correct answer: Vertical Multiplier (VM)
Lifting from floor level places the origin below knuckle height, significantly reducing the Vertical Multiplier and thus the RWL.
Question 3: What is the recommended maximum sustained pushing force for an average adult worker on a level surface according to ergonomic guidelines?
- Under 5 lbs (22 N)
- Under 20 lbs (89 N) (Correct answer)
- Under 50 lbs (222 N)
- Under 100 lbs (445 N)
Correct answer: Under 20 lbs (89 N)
Ergonomic guidelines generally recommend sustained horizontal push/pull forces not exceed approximately 20 lbs (89 N) to minimize injury risk.
Question 4: Which type of chair adjustment is most important for preventing pressure on the back of the thighs?
- Armrest height
- Seat pan depth (fore-aft) (Correct answer)
- Backrest lumbar support height
- Seat tilt angle
Correct answer: Seat pan depth (fore-aft)
Seat pan depth must leave 2–4 finger widths between the seat edge and the back of the knees to avoid popliteal pressure.
Question 5: A worker develops lateral epicondylitis ('tennis elbow'). Which workstation condition is the most likely ergonomic contributor?
- Monitor positioned too high
- Repetitive forearm pronation/supination with high grip force (Correct answer)
- Insufficient lumbar support
- Chair too low relative to desk
Correct answer: Repetitive forearm pronation/supination with high grip force
Lateral epicondylitis is associated with repetitive wrist extension and forearm rotation combined with forceful gripping, overloading the common extensor tendon.
Question 6: In ergonomic hierarchy of controls, which solution is considered more effective than administrative controls?
- Job rotation schedules
- Work-rest breaks
- Engineering controls such as lift assists (Correct answer)
- Ergonomics training programs
Correct answer: Engineering controls such as lift assists
Engineering controls physically change the task or environment, providing more reliable hazard reduction than administrative controls that rely on behavior.
Question 7: Which symptom pattern is most consistent with carpal tunnel syndrome (CTS) in a keyboard worker?
- Pain and weakness along the outer forearm and elbow
- Numbness and tingling in the thumb, index, and middle fingers, especially at night (Correct answer)
- Diffuse shoulder aching after prolonged sitting
- Lower back pain radiating to the buttocks
Correct answer: Numbness and tingling in the thumb, index, and middle fingers, especially at night
CTS compresses the median nerve, causing numbness and tingling in the thumb, index, and middle fingers, often worse at night.
CEA Workplace Ergonomic 3
Which anthropometric measure is most critical when setting seated workstation height for a diverse workforce?