COHN Ergonomics and Physical Hazards 3

Question 1

A construction worker is exposed to whole-body vibration from operating a jackhammer daily. The primary long-term health risk is:

Accepted Answer

Low back degeneration and disc disorders

Answer

Prolonged whole-body vibration is strongly associated with accelerated lumbar disc degeneration, low back pain, and spinal disorders.

Question 2

The Rapid Upper Limb Assessment (RULA) tool generates a grand score. A score of 7 indicates:

Accepted Answer

Immediate investigation and implementation of change

Answer

A RULA grand score of 7 (the maximum) indicates the highest action level, requiring immediate investigation and ergonomic change.

Question 3

When assessing thermal stress in a hot outdoor environment, which index accounts for humidity, radiant heat, and air movement?

Accepted Answer

Wet Bulb Globe Temperature (WBGT)

Answer

WBGT integrates dry bulb, wet bulb, and globe temperature readings to reflect the combined thermal stress of humidity, radiation, and air movement on a worker.

Question 4

A COHN is designing a workstation for data entry. The recommended elbow angle for keyboard use to minimize upper extremity strain is approximately:

Accepted Answer

70–90 degrees

Answer

A 90-degree (roughly neutral) elbow angle with the forearm parallel to the floor minimizes static load on shoulder and forearm muscles during keyboard tasks.

Question 5

Which of the following best describes the purpose of a job hazard analysis (JHA) in an ergonomics program?

Accepted Answer

To systematically identify ergonomic risk factors for each job task

Answer

A JHA breaks each job into tasks and analyzes the ergonomic risk factors (force, repetition, posture, vibration, contact stress) associated with each task.

COHN Exam Practice Test

COHN Exam Practice Test

COHN Ergonomics and Physical Hazards 3