Mixed Deck — All CES Topics Flashcards

What does the 'frequency multiplier' in the NIOSH Lifting Equation adjust for?

Answer: The number of lifts per minute and duration of the lifting task

The frequency multiplier reduces the RWL as lifting frequency and task duration increase, accounting for the cumulative metabolic and biomechanical fatigue associated with repeated lifts.

Conveyor height for repetitive assembly tasks should ideally be set at:

Answer: Elbow height of the standing worker

Setting conveyor or work surface height at elbow level minimizes shoulder elevation and allows the arms to work in a neutral, low-load zone.

Which method improves ergonomic training effectiveness?

Answer: Interactive and practical sessions

Ergonomic training is most effective when it allows participants to actively engage with the material. Interactive and practical sessions provide hands-on experience, enabling individuals to apply ergonomic principles directly to their work environment and understand how to implement changes, leading to better retention and behavioral change.

Which personal protective approach is considered a last resort in the hierarchy of controls for managing environmental stressors such as extreme heat or noise?

Answer: Personal protective equipment (cooling vests, earplugs)

PPE is at the bottom of the hierarchy of controls because it relies on worker compliance and does not reduce the hazard at its source, unlike elimination or engineering controls.

What is the primary ergonomic concern with a precision grip versus a power grip in industrial tasks?

Answer: Precision grip requires much higher relative muscle force and causes greater tendon loading for equivalent tasks

Precision grip uses a smaller contact area and fewer muscles, requiring proportionally greater effort to achieve the same force as power grip, resulting in higher muscle and tendon loading.

What percentage of the workday does OSHA suggest as a maximum continuous seated computer work before a break is recommended?

Answer: No more than 100% with microbreaks every hour

OSHA recommends short, frequent micro-breaks (5 minutes per hour) rather than limiting total proportion, to address cumulative static loading.

Which federal agency conducts research on ergonomic hazards but does NOT have regulatory enforcement authority?

Answer: NIOSH (National Institute for Occupational Safety and Health)

NIOSH is the research arm of CDC, conducting studies and making recommendations on occupational hazards including ergonomics, but enforcement authority rests with OSHA.

Sit-stand workstations are most beneficial when they are used:

Answer: With alternating sitting and standing throughout the day (e.g., 30-min intervals)

Alternating between sitting and standing at approximately 30-minute intervals prevents prolonged static loading in either posture and improves circulation.

Why is employee involvement important in ergonomic assessments?

Answer: To gain insights and improve compliance

Employee involvement is crucial because workers are the ones performing the tasks daily and often have the best understanding of job demands and potential stressors. Their input provides valuable insights into specific ergonomic issues that might not be apparent to an assessor, leading to more effective solutions. Furthermore, involving employees in the assessment and solution development process fosters a sense of ownership and increases their willingness to comply with and sustain ergonomic changes.

Anti-vibration gloves are most effective at reducing vibration in which frequency range?

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.

A proactive ergonomics program is distinguished from a reactive program primarily because it:

Answer: Identifies and controls hazards before injuries occur

Proactive programs use hazard identification methods (walk-throughs, assessments, leading indicators) to eliminate risks before they cause injury.

Which state currently has an enforceable ergonomics standard for general industry?

Answer: California

California's Division of Occupational Safety and Health (Cal/OSHA) enforces Title 8 regulations that include ergonomics program requirements for employers with recurring MSDs.

When should a sit-stand workstation be recommended as an ergonomic intervention?

Answer: When a worker must remain seated for extended periods without opportunity for postural variation

Sit-stand workstations are most beneficial when workers are required to sit for prolonged periods without opportunity for postural variation, reducing static loading on the spine.

When assessing noise exposure in a mixed-noise environment where a worker is exposed to different levels for different durations, which calculation method should the ergonomist apply?

Answer: Dose summation formula (C₁/T₁ + C₂/T₂ + … ≤ 1)

The noise dose summation formula (Σ Cᵢ/Tᵢ ≤ 1) combines exposures at different levels by expressing each as a fraction of the allowable time, ensuring total dose does not exceed 100%.

Workers' compensation data is most useful in an ergonomics program for:

Answer: Identifying body parts, departments, and tasks with the highest injury frequency and cost

Analyzing workers' compensation claims reveals injury patterns that help prioritize which departments, jobs, or body regions need ergonomic intervention first.

How do rest breaks help prevent injury?

Answer: They support recovery and prevent fatigue

Rest breaks are a critical component of ergonomic injury prevention, especially for tasks involving repetitive motions, sustained postures, or high physical demands. These breaks allow muscles and joints to recover from exertion, reducing the accumulation of fatigue and strain that can lead to musculoskeletal injuries. By interrupting continuous work, rest breaks help to restore physical and mental capacity, thereby preventing overuse injuries and maintaining performance.

Who should receive ergonomic training?

Answer: Everyone in the workplace

Ergonomic principles apply to virtually all work environments and tasks, from office settings to manufacturing floors. Therefore, comprehensive ergonomic training should be provided to everyone in the workplace, regardless of their specific role or seniority. This ensures that all employees understand how to work safely, identify potential hazards, and contribute to a culture of safety, ultimately reducing the overall risk of work-related injuries across the organization.

Which control measure is the most effective ergonomic intervention for reducing whole-body vibration exposure in vehicle operators?

Answer: Installing a suspension seat with a low-transmissibility rating

A suspension seat engineered to isolate the occupant from vehicle vibration is the primary engineering control for WBV, directly reducing the energy transmitted to the spine.

What does ANSI Z10 address in relation to ergonomics?

Answer: Occupational Health and Safety Management Systems that include ergonomics as a hazard category

ANSI Z10 is a voluntary Occupational Health and Safety Management System standard that incorporates ergonomic hazard identification and control within a systematic safety program framework.

Management commitment is considered essential in an ergonomics program primarily because it:

Answer: Provides resources, authority, and cultural support needed to implement changes

Without management commitment, ergonomic recommendations lack the funding, authority, and prioritization needed to be implemented and sustained.