Mixed Deck — All CEA Topics Flashcards

When validating a workplace ergonomics intervention, the MOST objective outcome measure for upper-extremity disorder risk reduction is:

Answer: Pre- and post-intervention RULA or REBA scores

Comparing validated observational tool scores (e.g., RULA, REBA) before and after an intervention provides an objective, quantified measure of postural risk change.

The CREAM (Cognitive Reliability and Error Analysis Method) approach to human reliability analysis differs from THERP primarily because CREAM:

Answer: Emphasizes context and performance conditions rather than task decomposition alone

CREAM centers on the cognitive context — factors like crew collaboration, interface quality, and time pressure — that shape reliability, whereas THERP decomposes tasks into behavioral steps with HEP tables.

Which variable does the frequency multiplier (FM) in the NIOSH lifting equation account for?

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

The frequency multiplier reduces the RWL as lifts per minute and total lifting duration increase, reflecting cumulative fatigue and tissue recovery limits.

When evaluating a push/pull task using the Liberty Mutual Psychophysical Tables, the primary variable affecting acceptable force limits is:

Answer: Task frequency, distance, and height of force application

The Liberty Mutual tables account for frequency of exertion, distance traveled, and the height at which force is applied to determine acceptable limits.

Which keyboard design feature MOST benefits users who are susceptible to wrist extension injuries?

Answer: Negative tilt (front edge higher than back edge) to keep wrists flat or slightly extended downward

Negative tilt positions the keyboard so wrists remain flat or in slight flexion rather than extension, reducing carpal tunnel pressure during typing.

What documentation practice is considered essential in Industrial Ergonomics within the Certified Ergonomics Associate field?

Answer: Recording actions, observations, and outcomes in real-time or as close to the event as possible

Real-time or near-real-time documentation in Industrial Ergonomics ensures accuracy, provides a contemporaneous record, and is considered the gold standard for professional accountability and legal defensibility.

Which cognitive work analysis method involves workers verbalizing their thought processes in real time during task performance?

Answer: Think-aloud protocol (verbal protocol analysis)

The think-aloud protocol captures cognitive processes, mental workload, confusion points, and decision strategies by having participants verbalize their thoughts while performing a task.

A participatory ergonomics program differs from a traditional ergonomics program primarily because it:

Answer: Actively involves workers in identifying hazards and designing solutions

Participatory ergonomics engages workers as active collaborators in hazard identification and solution development, improving both solution quality and worker buy-in.

Which element of an effective MSD prevention program ensures that interventions remain effective as tasks and workforces change over time?

Answer: Periodic program evaluation and continuous improvement processes

Continuous improvement processes — including periodic reassessment, tracking MSD trends, and updating controls — ensure an MSD prevention program adapts to changing work conditions.

Which of the following best supports an effective ergonomics program?

Answer: Management commitment

Management commitment ensures resources, accountability, and long-term success of ergonomics programs.

When a worker's elbows are consistently elevated above 30° during a keyboard task, the ergonomist's first corrective recommendation should address:

Answer: Work surface height being too high relative to elbow height

Elevated elbows during keyboard use typically indicate the work surface is too high; lowering the desk or raising the seat can restore neutral shoulder and elbow posture.

Cognitive tunneling (attentional tunneling) in high-demand work environments is characterized by:

Answer: Excessive focus on one information source while critical information from other sources is ignored

Cognitive tunneling occurs when attentional resources are locked onto a single task or display, causing the operator to miss important signals or events in the broader environment.

Which lighting condition is MOST likely to cause computer vision syndrome at a workstation?

Answer: Overhead fluorescent lighting directly above the monitor causing veiling reflections

Overhead fluorescent lights positioned directly above and behind a monitor create veiling reflections on the screen, forcing users to strain their eyes to see content.

A tool with a bent (pistol-grip) handle is most beneficial when the work surface is:

Answer: At waist height with a horizontal work surface

A pistol-grip handle keeps the wrist in a neutral position when working on a horizontal surface at waist height, avoiding wrist extension or flexion.

Which document holder placement best reduces neck strain for a user who frequently references paper documents while typing?

Answer: Between the monitor and keyboard at the same height and distance as the monitor

Placing the document holder at the same height and distance as the monitor minimizes head turning and focal distance changes between the document and screen.

A squeeze force measurement of 32 lbs is recorded during a gripping task. According to ergonomic guidelines, this level would most likely be classified as:

Answer: Moderate to high force requiring evaluation

Grip forces above approximately 10 lbs for repetitive tasks are generally considered moderate-to-high risk requiring ergonomic evaluation.

A warehouse team must move pallets weighing up to 500 lbs. Which powered equipment selection criterion is MOST important from an ergonomic standpoint?

Answer: Operator posture and visibility while driving

Operator posture and sightlines directly affect musculoskeletal loading and fatigue during prolonged powered equipment use.

In dual-task experiments, the psychological refractory period (PRP) refers to the delay in responding to a second stimulus because:

Answer: Central processing of the first task blocks processing of the second

The PRP occurs because humans have a central processing bottleneck; the cognitive response-selection stage for the second task must wait until the first is complete.

What is the ergonomic significance of the 'duty cycle' in hand-intensive work?

Answer: Proportion of time the worker is exerting force versus resting within a cycle

Duty cycle is the ratio of work time to total cycle time; a high duty cycle means minimal recovery, leading to faster muscle fatigue and higher injury risk.

A surgeon selects laparoscopic instruments for a 3-hour procedure. Which handle design principle from ergonomics MOST applies to reduce forearm muscle fatigue?

Answer: Using palm-grip handles aligned with the instrument shaft to eliminate forearm pronation

Palm-grip handles aligned along the shaft axis keep the forearm in a neutral rotation, eliminating the sustained forearm pronation that is the dominant driver of forearm fatigue in laparoscopic surgery.