ASP Workplace Ergonomics 5 — Questions and Answers
Question 1: A warehouse worker reports tingling in the ring and little fingers of both hands. Which nerve is most likely being compressed, and what structure is implicated?
- Median nerve at the carpal tunnel
- Ulnar nerve at Guyon's canal or the elbow (Correct answer)
- Radial nerve at the lateral epicondyle
- Brachial plexus at the thoracic outlet
Correct answer: Ulnar nerve at Guyon's canal or the elbow
Tingling in the ring and little fingers indicates ulnar nerve compression, which can occur at Guyon's canal in the wrist or at the cubital tunnel at the elbow from sustained elbow flexion or pressure.
Question 2: When applying the Rapid Entire Body Assessment (REBA) tool, a score of 11 or higher indicates which level of action?
- Low risk — no action needed
- Medium risk — action may be needed
- High risk — action needed soon
- Very high risk — implement changes immediately (Correct answer)
Correct answer: Very high risk — implement changes immediately
REBA scores of 11–15 indicate a very high risk level requiring immediate ergonomic intervention to prevent musculoskeletal injury.
Question 3: Which ergonomic principle supports using a pistol-grip power tool instead of an in-line (straight) tool for a horizontal fastening task at elbow height?
- Reducing grip force required
- Keeping the wrist in a neutral (straight) position (Correct answer)
- Minimizing tool weight and vibration
- Improving torque reaction control
Correct answer: Keeping the wrist in a neutral (straight) position
A pistol-grip handle allows the wrist to remain straight (neutral) when working in a horizontal plane, reducing ulnar/radial deviation that causes MSD risk.
Question 4: The Composite Lifting Index (CLI) in the Revised NIOSH Lifting Equation is used for:
- Single-task jobs with variable load weights
- Multi-task jobs where workers perform several different lifting tasks (Correct answer)
- Team lifts involving two or more workers simultaneously
- Jobs combining pushing, pulling, and lifting in the same cycle
Correct answer: Multi-task jobs where workers perform several different lifting tasks
The CLI extends the NIOSH Lifting Equation to evaluate the overall ergonomic risk for jobs that include multiple distinct lifting tasks performed during a single work shift.
Question 5: Which of the following risk factors is UNIQUE to whole-body vibration (WBV) exposure compared to upper-extremity musculoskeletal risk?
- Increased risk of lower back disorders and spinal degeneration (Correct answer)
- Elevated risk of carpal tunnel syndrome
- Raynaud's phenomenon (white finger disease)
- Increased tendinitis of the shoulder rotator cuff
Correct answer: Increased risk of lower back disorders and spinal degeneration
WBV, from operating heavy equipment or vehicles, is uniquely associated with lower back pain and intervertebral disc degeneration due to resonance with spinal structures around 4–12 Hz.
Question 6: An ergonomics program metric shows a 35% reduction in workers' compensation costs after intervention. This is an example of which type of program evaluation?
- Process measure
- Leading indicator
- Lagging indicator (Correct answer)
- Hazard assessment benchmark
Correct answer: Lagging indicator
Workers' compensation cost reduction is a lagging indicator because it measures outcomes (injuries/costs already incurred) rather than proactive upstream program activities.
Question 7: Per ACGIH TLV guidelines, the maximum recommended weight for a one-handed lift from knuckle to shoulder height in an optimal (close, symmetric) condition is approximately:
- 5 lbs (2.3 kg)
- 15 lbs (6.8 kg) (Correct answer)
- 25 lbs (11.3 kg)
- 35 lbs (15.9 kg)
Correct answer: 15 lbs (6.8 kg)
ACGIH TLV guidelines for manual material handling limit one-handed lifts in optimal conditions to approximately 15 lbs (6.8 kg) to protect the shoulder and spine.
ASP Workplace Ergonomics 5
A warehouse worker reports tingling in the ring and little fingers of both hands.
Which nerve is most likely being compressed, and what structure is implicated?