CIH CIH Ergonomics & Human Factors 2 — Questions and Answers
Question 1: Which observational ergonomic assessment tool uses a body posture coding system to rate the risk of upper-extremity disorders?
- NIOSH Lifting Equation
- RULA (Rapid Upper Limb Assessment) (Correct answer)
- OSHA 300 Log analysis
- ACGIH TLV for hand activity
Correct answer: RULA (Rapid Upper Limb Assessment)
RULA (Rapid Upper Limb Assessment) scores postures of the upper arm, lower arm, wrist, neck, trunk, and legs to estimate musculoskeletal risk levels.
Question 2: The ACGIH TLV for Hand Activity Level (HAL) uses what two variables to determine acceptable hand-intensive work limits?
- Force and temperature
- Frequency and duration
- Hand Activity Level and peak hand force (Correct answer)
- Weight lifted and distance traveled
Correct answer: Hand Activity Level and peak hand force
The ACGIH HAL TLV plots Hand Activity Level (0–10 scale of exertion frequency and recovery) against normalized peak hand force to identify action limit and TLV boundaries.
Question 3: What is the primary goal of an ergonomic job hazard analysis (JHA)?
- Calculate PELs for chemical exposures
- Identify and control ergonomic risk factors before injury occurs (Correct answer)
- Determine workers' compensation premium rates
- Measure noise dose for hearing conservation
Correct answer: Identify and control ergonomic risk factors before injury occurs
An ergonomic JHA systematically identifies task-level ergonomic stressors and prioritizes engineering, administrative, or PPE controls to prevent MSDs.
Question 4: Whole-body vibration (WBV) is primarily associated with which occupational setting?
- Office workers at standing desks
- Operators of vehicles and heavy mobile equipment (Correct answer)
- Assembly line workers with repetitive hand tasks
- Construction workers using hand drills
Correct answer: Operators of vehicles and heavy mobile equipment
WBV affects workers operating forklifts, trucks, tractors, and heavy equipment, with vibration transmitted through the seat or floor to the entire body, contributing to low back disorders.
Question 5: Which hierarchy of controls is MOST preferred when addressing an identified ergonomic hazard?
- Administrative controls such as job rotation
- Personal protective equipment
- Engineering controls such as redesigning the workstation (Correct answer)
- Training workers on proper lifting technique
Correct answer: Engineering controls such as redesigning the workstation
Engineering controls (workstation redesign, tool modification, mechanical assists) are most effective because they eliminate or reduce the hazard at the source.
Question 6: Awkward postures that increase musculoskeletal injury risk include working with the wrist in what position?
- Neutral (straight alignment)
- Radial or ulnar deviation exceeding 15° (Correct answer)
- Fully extended elbow at side
- Shoulder at 30° flexion with elbow supported
Correct answer: Radial or ulnar deviation exceeding 15°
Wrist radial or ulnar deviation beyond 15° increases tendon and nerve strain, substantially raising the risk of cumulative trauma disorders.
CIH CIH Ergonomics & Human Factors 2
Which observational ergonomic assessment tool uses a body posture coding system to rate the risk of upper-extremity disorders?