CES Office Ergonomics & Computer Workstations 2 — Questions and Answers
Question 1: What is the recommended minimum seat pan depth adjustment range for office chairs?
- 1 inch
- 2–4 inches (Correct answer)
- 6–8 inches
- 10 inches
Correct answer: 2–4 inches
A seat pan depth range of 2–4 inches accommodates variation in thigh length while maintaining 2–3 finger-widths of clearance behind the knee.
Question 2: The 20-20-20 rule for computer users recommends:
- 20 minutes work, 20 second stretch, 20 reps
- Every 20 minutes look at something 20 feet away for 20 seconds (Correct answer)
- 20 pound weight limit every 20 minutes for 20 seconds
- 20 minutes seated, 20 minutes standing, 20 minute walk
Correct answer: Every 20 minutes look at something 20 feet away for 20 seconds
The 20-20-20 rule helps reduce digital eye strain by giving the ciliary muscles a rest through distant focusing every 20 minutes.
Question 3: An ergonomic mouse should be selected primarily based on which criterion?
- Wireless capability
- Hand size and grip style of the user (Correct answer)
- Number of programmable buttons
- DPI sensitivity level
Correct answer: Hand size and grip style of the user
Mouse fit to hand size and grip style (palm, claw, or fingertip) is the primary criterion because a poorly sized mouse causes sustained awkward postures.
Question 4: Which type of office lighting arrangement best reduces veiling reflections on monitor screens?
- Overhead fluorescent lights directly above the monitor
- Luminaires placed parallel to and between workstations (Correct answer)
- Desk lamp aimed at the screen
- Natural light behind the monitor
Correct answer: Luminaires placed parallel to and between workstations
Placing overhead luminaires parallel to workstation rows and between workstations prevents direct overhead light from reflecting off monitor screens into the user's eyes.
Question 5: Which standard provides ergonomic guidelines specifically for office workstations with display screen equipment in the US?
- ISO 9241
- ANSI/HFES 100 (Correct answer)
- ASTM E1332
- OSHA 1910.147
Correct answer: ANSI/HFES 100
ANSI/HFES 100 (Human Factors Engineering of Computer Workstations) provides US-specific dimensional and design recommendations for display screen workstations.
Question 6: A footrest is most beneficial when:
- The worker prefers standing
- The chair cannot be raised enough to support neutral posture without leaving feet dangling (Correct answer)
- The worker uses a sit-stand desk
- The floor surface is carpeted
Correct answer: The chair cannot be raised enough to support neutral posture without leaving feet dangling
When desk height is fixed and the chair must be raised to reach the keyboard, a footrest supports the feet and restores thigh-to-torso angle.
CES Office Ergonomics & Computer Workstations 2
What is the recommended minimum seat pan depth adjustment range for office chairs?