CES Ergonomic Tools, Equipment & Technology 2 — Questions and Answers
Question 1: What is the primary ergonomic advantage of a pistol-grip power tool over an inline (straight) grip tool for horizontal work surfaces?
- Higher torque output
- Allows neutral wrist position when working on horizontal surfaces (Correct answer)
- Lighter weight distribution
- Less vibration transmission
Correct answer: Allows neutral wrist position when working on horizontal surfaces
A pistol grip aligns the forearm so the wrist remains neutral when driving fasteners into horizontal surfaces, whereas an inline grip requires wrist extension.
Question 2: In ergonomic lighting assessment, a lux meter measures:
- Luminance (surface brightness)
- Illuminance (light falling on a surface) (Correct answer)
- Color rendering index
- Glare index
Correct answer: Illuminance (light falling on a surface)
A lux meter measures illuminance — the amount of light falling on a surface — which is compared to recommended levels for different task types.
Question 3: Spring-loaded scissors (with return spring) are recommended ergonomically because they:
- Increase cutting force
- Eliminate the opening stroke muscle effort, reducing fatigue (Correct answer)
- Reduce blade sharpness needs
- Are lighter than standard scissors
Correct answer: Eliminate the opening stroke muscle effort, reducing fatigue
The return spring passively opens the scissor blades, removing the need for the extensor muscles to actively open the fingers after each cut, halving cumulative exertion.
Question 4: Exoskeleton devices used in industrial ergonomics primarily aim to:
- Monitor worker heart rate
- Augment or offload forces on specific body segments during demanding tasks (Correct answer)
- Replace manual labor entirely
- Provide thermal insulation
Correct answer: Augment or offload forces on specific body segments during demanding tasks
Passive or powered exoskeletons redistribute load from vulnerable body regions (e.g., lumbar spine, shoulders) to stronger structures or actuators, reducing musculoskeletal strain.
Question 5: What is the recommended minimum handle diameter for a power grip on hand tools?
- 0.5–0.75 inch
- 1.25–2.0 inches (Correct answer)
- 3.0–3.5 inches
- 4.0–5.0 inches
Correct answer: 1.25–2.0 inches
Handle diameters of 1.25–2.0 inches (30–50 mm) allow maximum grip force generation and minimize contact stress on the palm.
Question 6: Anti-vibration gloves are most effective at reducing vibration in which frequency range?
- Below 10 Hz
- 25–200 Hz (Correct answer)
- 500–1000 Hz
- Above 2000 Hz
Correct answer: 25–200 Hz
Anti-vibration gloves provide meaningful attenuation primarily in the 25–200 Hz range; they are less effective at lower frequencies where most powerful tools operate.
CES Ergonomic Tools, Equipment & Technology 2
What is the primary ergonomic advantage of a pistol-grip power tool over an inline (straight) grip tool for horizontal work surfaces?