NSC Ergonomics 5 — Questions and Answers
Question 1: Which NSC ergonomics concept describes redesigning a task so that the heaviest or most awkward part of the job is performed less frequently?
- Task enlargement
- Job rotation
- Task redesign (Correct answer)
- Work hardening
Correct answer: Task redesign
Task redesign permanently modifies how a job is performed to reduce exposure to ergonomic risk factors at the source.
Question 2: Which of the following is a sign that a worker's chair is NOT properly adjusted for ergonomic seating?
- Feet are flat on the floor
- Thighs are parallel to the floor
- Lower back is unsupported and rounded (Correct answer)
- Knees are at approximately 90 degrees
Correct answer: Lower back is unsupported and rounded
A rounded lower back (loss of lumbar curve) indicates the chair's lumbar support or seat pan angle is not adjusted correctly.
Question 3: What is the recommended maximum angle of wrist extension or flexion during repetitive tasks to reduce MSD risk?
- 45 degrees
- 15 degrees (Correct answer)
- 30 degrees
- 60 degrees
Correct answer: 15 degrees
NSC and ergonomic guidelines recommend keeping wrist deviation below 15 degrees from neutral to minimize injury risk during repetitive work.
Question 4: A truck driver develops low back pain after years of long-distance driving. Which ergonomic intervention would MOST directly address whole-body vibration exposure?
- Strengthening core muscles through off-duty exercise
- Installing a suspension seat with vibration-dampening capability (Correct answer)
- Using a seat belt at all times
- Adjusting the rearview mirror
Correct answer: Installing a suspension seat with vibration-dampening capability
Suspension seats with vibration-dampening systems directly attenuate whole-body vibration transmission from the vehicle to the driver.
Question 5: Which of the following administrative controls helps manage ergonomic risk in a high-repetition assembly job?
- Purchasing ergonomic hand tools
- Implementing scheduled micro-breaks and job rotation (Correct answer)
- Installing anti-fatigue matting
- Adjusting conveyor belt height
Correct answer: Implementing scheduled micro-breaks and job rotation
Micro-breaks and job rotation are administrative controls that reduce cumulative exposure time to repetitive motion risk factors.
Question 6: In ergonomic lifting guidelines, what is the recommended zone for lifting loads to minimize spine stress?
- Below knee height
- Knuckle to shoulder height (power zone) (Correct answer)
- Above shoulder height
- At ankle height
Correct answer: Knuckle to shoulder height (power zone)
The 'power zone' — roughly knuckle to shoulder height — keeps lifts closest to the body's center of gravity, minimizing spine loading.
Question 7: Which MSD is characterized by numbness, tingling, and pain in the thumb, index, and middle fingers due to nerve compression at the wrist?
- Trigger finger
- Lateral epicondylitis
- Carpal tunnel syndrome (Correct answer)
- De Quervain's tenosynovitis
Correct answer: Carpal tunnel syndrome
Carpal tunnel syndrome results from compression of the median nerve within the carpal tunnel, causing symptoms in the thumb, index, and middle fingers.
NSC Ergonomics 5
Which NSC ergonomics concept describes redesigning a task so that the heaviest or most awkward part of the job is performed less frequently?