CES Human Factors & Biomechanics 2

Question 1

What is the primary purpose of an electromyography (EMG) assessment in ergonomic studies?

Accepted Answer

Measure muscle activation and fatigue during tasks

Answer

EMG measures electrical activity in muscles, allowing ergonomists to quantify muscle effort, identify overexertion, and document fatigue patterns during work tasks.

Question 2

Which factor primarily determines the compression load experienced at the L5/S1 disc during lifting?

Accepted Answer

Horizontal distance of the load from the spine

Answer

The horizontal distance of the load from the lumbar spine is the primary multiplier of compression force at L5/S1, often having more impact than load weight alone.

Question 3

What does the anthropometric concept of 'design for the 5th to 95th percentile' mean in ergonomics?

Accepted Answer

Designing workstations to accommodate 90% of the target population

Answer

Designing for the 5th to 95th percentile means the workspace accommodates 90% of users, balancing practical design constraints with broad usability.

Question 4

Which type of muscle contraction is most associated with the development of localized muscle fatigue during sustained work?

Accepted Answer

Static (isometric) contraction

Answer

Static contractions restrict blood flow to working muscles, impairing oxygen delivery and metabolite clearance, leading to rapid localized fatigue.

Question 5

What is the 'action limit' concept originally developed for in ergonomics?

Accepted Answer

Identifying acceptable manual lifting loads using NIOSH guidelines

Answer

The NIOSH action limit was developed as a guideline to identify manual lifting conditions that exceed acceptable risk levels and require ergonomic intervention.

CES - Certified Ergonomic Specialist Practice Test

CES - Certified Ergonomic Specialist Practice Test

CES Human Factors & Biomechanics 2