Mixed Deck — All CPE Topics Flashcards

What is 'contact stress' in ergonomics?

Answer: Localized mechanical pressure on soft tissue from hard surfaces or edges

Contact stress occurs when a hard surface or edge concentrates mechanical pressure on a small area of soft tissue, impairing circulation and nerve function.

Body mass index (BMI) is relevant to ergonomic design primarily because elevated BMI is associated with:

Answer: Increased soft tissue dimensions that affect clearance requirements, seat width, and support surfaces

Higher BMI is associated with greater soft tissue bulk beyond what skeletal measurements predict, requiring adjustments to seat width, armrest spacing, and workspace clearances to accommodate larger body girths.

How can task design be modified to improve ergonomics?

Answer: By modifying tasks to reduce physical strain and improve comfort

Task design in ergonomics involves analyzing and restructuring work processes to make them less physically demanding and more efficient. This can include reducing repetitive motions, minimizing heavy lifting, optimizing reach distances, or incorporating micro-breaks. By modifying tasks to better suit human capabilities, it reduces physical strain, prevents injuries, and enhances overall worker comfort and productivity.

What is 'inattentional blindness' in human factors?

Answer: Failure to notice unexpected stimuli when attention is focused elsewhere

Inattentional blindness occurs when an individual fails to perceive an unexpected but visible stimulus because attention is directed toward another task.

Which posture assessment tool specifically accounts for both upper and lower body posture including load and activity type?

Answer: REBA

REBA (Rapid Entire Body Assessment) evaluates whole-body posture including upper and lower extremities, load handled, and activity level.

Why is employee training an essential part of ergonomic interventions?

Answer: To educate employees on proper ergonomics and reduce injury risks

Employee training is a cornerstone of effective ergonomic interventions because even the best-designed workstation can be misused without proper knowledge. Training teaches employees how to adjust their equipment, maintain good posture, recognize early signs of discomfort, and incorporate micro-breaks. This empowers them to actively participate in their own well-being and significantly reduces the risk of work-related injuries.

Job rotation as an ergonomic administrative control is intended to achieve what primary benefit?

Answer: Reduce individual exposure duration to specific ergonomic risk factors by distributing tasks

Job rotation distributes ergonomic exposures across workers or across time, reducing any individual's cumulative exposure to a specific stressor such as repetitive motion.

When secular trend data indicates a workforce is becoming taller over time, ergonomists should respond by:

Answer: Using the most recent available anthropometric datasets or applying secular trend correction factors

Because secular trend causes older datasets to systematically underestimate current population dimensions, ergonomists should use the most recent survey data or apply documented correction factors to older data.

Why is task variety important in ergonomic workplace design?

Answer: To minimize repetitive motions and prevent injury

Task variety is a key ergonomic strategy to combat the risks associated with repetitive strain injuries (RSIs). By rotating tasks or incorporating different types of movements, employees use different muscle groups and avoid prolonged stress on any single part of the body. This reduces fatigue, discomfort, and the likelihood of developing musculoskeletal disorders.

Which metric is used to evaluate the effectiveness of an ergonomics program in reducing injuries over time?

Answer: Total Recordable Incident Rate (TRIR)

TRIR (Total Recordable Incident Rate) measures recordable injuries per 100 full-time workers and is the standard lagging indicator for evaluating injury prevention program effectiveness.

What is the importance of workstation layout in ergonomics?

Answer: To ensure that tools and materials are within easy reach, reducing strain

An optimized workstation layout is fundamental to ergonomics, focusing on arranging tools, equipment, and materials efficiently. By keeping frequently used items within the worker's primary reach zone, it minimizes unnecessary stretching, twisting, and reaching. This reduces physical strain, improves workflow, and enhances overall efficiency and comfort.

The impact of clothing and personal protective equipment (PPE) on workstation anthropometric design is typically addressed by:

Answer: Adding functional allowances to nude anthropometric measurements to account for added bulk

Most anthropometric databases collect nude measurements; ergonomists add functional allowances (additional millimeters) to account for clothing thickness, PPE bulk, and restricted movement before applying data to design.

What is the importance of workstation ergonomics in preventing musculoskeletal disorders?

Answer: To reduce physical strain and prevent musculoskeletal disorders

Workstation ergonomics focuses on optimizing the interaction between the worker and their immediate work environment to minimize physical stressors. By ensuring proper setup of monitors, keyboards, chairs, and other equipment, it helps maintain neutral postures and reduces repetitive motions or excessive force. This directly prevents the development of musculoskeletal disorders (MSDs) like carpal tunnel syndrome or back pain, which are common work-related injuries.

De Quervain's tenosynovitis specifically affects which tendons?

Answer: Abductor pollicis longus and extensor pollicis brevis

De Quervain's tenosynovitis is inflammation of the abductor pollicis longus and extensor pollicis brevis tendons at the wrist's radial side.

An ergonomics team conducts a structured walkthrough and rates tasks using a 3-point scale (low/medium/high risk). This approach is best described as:

Answer: Semi-quantitative screening

Semi-quantitative screening uses ordered scales to prioritize risks without the precision of full biomechanical measurement.

Which factor does NOT directly increase the biomechanical stress of a manual lift?

Answer: Eye color of the worker

Eye color is a personal characteristic unrelated to biomechanical stress; horizontal distance, frequency, and twisting all amplify spinal loading.

Which measure is used in RULA to differentiate between muscle use that is static versus repeated?

Answer: Muscle use score (+1 for static posture held >1 min or repeated >4x/min)

RULA adds a +1 muscle use score when a posture is held statically for more than one minute or repeated more than four times per minute.

How can ergonomics improve workplace productivity?

Answer: By reducing physical strain and promoting better posture

Ergonomics improves workplace productivity by designing tasks and environments that minimize physical strain, fatigue, and discomfort for employees. When workers are more comfortable and less prone to injury, they can focus better, work more efficiently, and maintain higher levels of output.

The 'population stereotype' for the direction of rotation of a control to increase a parameter in North America is:

Answer: Clockwise

In North America, the population stereotype for rotary controls is clockwise rotation to increase a value (e.g., increase volume, temperature).

What role does posture play in preventing musculoskeletal disorders?

Answer: Proper posture reduces physical strain and risk of musculoskeletal disorders

Proper posture aligns the body correctly, distributing stress evenly across muscles and joints. This minimizes strain on specific areas, preventing overuse injuries and reducing the likelihood of developing musculoskeletal disorders like back pain or carpal tunnel syndrome over time. It is a fundamental aspect of ergonomic health.