Industrial Ergonomics Flashcards
7 cards from real CEA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Industrial Ergonomics flashcards as text
Which measurement tool is used to directly quantify electromyographic (EMG) muscle activity in industrial ergonomics research?
Answer: Surface or fine-wire electrodes connected to an EMG amplifier
EMG measures electrical signals produced by muscle fibers via surface or fine-wire electrodes, allowing quantification of muscle activation levels and fatigue.
A packing line requires workers to reach across a 36-inch wide conveyor to place items. The PRIMARY ergonomic concern is:
Answer: Horizontal reach exceeding acceptable limits causing shoulder and trunk loading
Reaching across a 36-inch conveyor creates a large horizontal distance, forcing the trunk to flex forward and shoulders to extend beyond safe reach envelopes.
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.
According to OSHA ergonomics guidance, which factor is NOT one of the primary ergonomic risk factors for MSDs?
Answer: Worker age
The primary ergonomic MSD risk factors are force, repetition, awkward posture, contact stress, vibration, and temperature — worker age is a susceptibility factor, not a primary risk factor.
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.
In an ergonomic risk assessment, 'contact stress' is best described as:
Answer: Localized mechanical compression of soft tissue against a hard edge or surface
Contact stress occurs when hard surfaces or edges press into soft tissue (e.g., a bench edge against the forearm), compressing nerves, tendons, and blood vessels.
Which industrial task modification BEST addresses the ergonomic risk of sustained static loading?
Answer: Introducing micro-breaks or brief postural changes within the task
Micro-breaks or postural changes interrupt sustained muscle activation, allowing blood flow to restore oxygen and remove metabolic byproducts, reducing fatigue.