Ergonomics & Musculoskeletal Disorder Prevention Flashcards

Which Liberty Mutual Manual Materials Handling tables (Snook Tables) are primarily used to determine acceptable weights and forces for ergonomic task design?

Answer: Psychophysical acceptable weight limits for specified percentages of the working population

The Snook (Liberty Mutual) Tables are based on psychophysical methodology, providing acceptable force and weight limits for various MMH tasks that a specified percentage of the industrial working population can perform without overstress.

Tendinitis of the rotator cuff is most associated with which ergonomic risk factor?

Answer: Sustained or repeated overhead work above shoulder height

Sustained or repetitive overhead work requires the rotator cuff muscles to maintain the shoulder in an elevated position, increasing compressive forces on the supraspinatus tendon and raising tendinitis risk.

Which ergonomic principle does 'job rotation' represent in the hierarchy of controls?

Answer: Administrative control

Job rotation is an administrative control that limits individual exposure duration to a specific ergonomic risk by distributing the cumulative physical load across multiple workers.

The RULA (Rapid Upper Limb Assessment) tool assigns a final action level of 4, which requires:

Answer: Investigation and changes immediately

A RULA final action level of 4 (score 7+) indicates high-risk postures requiring immediate investigation and corrective action to prevent musculoskeletal injury.

Which of the following best describes 'contact stress' as an ergonomic risk factor?

Answer: Mechanical pressure on soft tissue from hard, sharp, or narrow surfaces

Contact stress occurs when hard or narrow surfaces exert localized mechanical pressure on soft tissue (e.g., wrist resting on a desk edge), compressing nerves and blood vessels and increasing MSD risk.

An ergonomics program audit should evaluate which of the following elements to confirm program effectiveness?

Answer: MSD injury and illness rates, near-miss reports, and worker symptom surveys before and after interventions

Effective ergonomics program audits measure outcomes such as MSD rates, near-miss trends, and symptom prevalence to determine whether interventions are reducing injury risk.

Which vibration metric is used to assess whole-body vibration exposure and is compared against ISO 2631-1 health guidance caution zones?

Answer: Frequency-weighted root mean square (r.m.s.) acceleration (m/s²)

ISO 2631-1 uses the frequency-weighted root mean square acceleration (in m/s²) to characterize whole-body vibration exposure and compare it against health guidance caution zones for low-back and other health effects.