NSC Ergonomics 4 — Questions and Answers
Question 1: Which ergonomic risk factor is defined as the number of times a motion or exertion is performed within a given time period?
- Force
- Repetition (Correct answer)
- Posture
- Duration
Correct answer: Repetition
Repetition refers to how frequently a motion or exertion is performed, and high repetition rates are a primary ergonomic risk factor for MSDs.
Question 2: What is the NSC-recommended approach when an ergonomic hazard cannot be eliminated entirely?
- Train workers to tolerate discomfort
- Apply multiple controls in combination (hierarchy of controls) (Correct answer)
- Issue personal protective equipment only
- Rotate workers to the same task
Correct answer: Apply multiple controls in combination (hierarchy of controls)
When hazards can't be eliminated, combining engineering, administrative, and PPE controls from the hierarchy offers the best protection.
Question 3: A production line worker experiences pain in the tendons of the forearm. This condition is MOST consistent with which MSD?
- Herniated disc
- Tendinitis (Correct answer)
- Raynaud's phenomenon
- Thoracic outlet syndrome
Correct answer: Tendinitis
Tendinitis is inflammation of tendons, commonly affecting the forearm of workers performing repetitive gripping or twisting motions.
Question 4: Which ergonomic guideline addresses the risk of awkward posture by specifying elbow height for work surface placement?
- Work surfaces should be set at wrist height while seated
- Work surfaces for precision tasks should be slightly above elbow height (Correct answer)
- Work surfaces should always be at shoulder height
- All work surfaces should be adjustable only for standing tasks
Correct answer: Work surfaces for precision tasks should be slightly above elbow height
Precision tasks benefit from a surface slightly above elbow height to support the forearms and provide close visual access without neck flexion.
Question 5: In ergonomics, 'duration' as a risk factor refers to:
- The total weight lifted during a shift
- The length of time a worker is exposed to a hazardous condition or posture (Correct answer)
- The speed at which a task is completed
- The number of workers performing the same task
Correct answer: The length of time a worker is exposed to a hazardous condition or posture
Duration measures how long a worker is continuously exposed to a risk factor, with longer exposures increasing injury risk.
Question 6: Which ergonomic principle supports the use of jigs, fixtures, and clamps on an assembly line?
- Reducing the weight of the load
- Eliminating the need for static holding postures (Correct answer)
- Increasing repetition speed
- Improving workplace lighting
Correct answer: Eliminating the need for static holding postures
Jigs and fixtures hold parts in place so workers don't have to sustain static grip or awkward arm positions, reducing MSD risk.
Question 7: What does a workplace ergonomic assessment typically involve as a first step?
- Purchasing new furniture immediately
- Identifying and evaluating existing ergonomic risk factors at workstations (Correct answer)
- Filing a workers' compensation claim
- Hiring an outside physical therapist
Correct answer: Identifying and evaluating existing ergonomic risk factors at workstations
The first step in an ergonomic assessment is identifying and evaluating risk factors such as awkward postures, repetition, and force demands.
NSC Ergonomics 4
Which ergonomic risk factor is defined as the number of times a motion or exertion is performed within a given time period?