CIEE Repetitive Motion & CTD Prevention 2

Question 1

A production line worker performs the same pinching motion 3,000 times per shift. Which factor MOST directly amplifies the CTD risk from this repetition rate?

Accepted Answer

Simultaneous forceful grip exceeding 10% MVC

Answer

Force and repetition interact multiplicatively, so combining high repetition with force exceeding ~10% of maximum voluntary contraction dramatically increases cumulative tissue load.

Question 2

Which physiological structure is PRIMARILY damaged in de Quervain's tenosynovitis, a common CTD in assembly workers?

Accepted Answer

Abductor pollicis longus and extensor pollicis brevis tendons

Answer

De Quervain's tenosynovitis involves inflammation of the tendon sheaths surrounding the abductor pollicis longus and extensor pollicis brevis at the radial styloid.

Question 3

An ergonomic evaluator observes a job with a Strain Index score of 12. What does this indicate about CTD risk?

Accepted Answer

High risk; the job is probably hazardous and redesign is warranted

Answer

A Strain Index score ≥7 is generally considered hazardous, and a score of 12 indicates the job is likely to cause upper-extremity CTDs and requires intervention.

Question 4

Micro-break schedules are most effective at reducing CTD risk when breaks are structured to allow which physiological process to occur?

Accepted Answer

Tissue perfusion and metabolite clearance from tendons

Answer

Short, frequent breaks allow blood flow to restore oxygen and clear lactate and other metabolites from avascular tendon tissue, reducing cumulative damage.

Question 5

Which NIOSH revised lifting equation variable specifically accounts for repetitive lifting over a full work shift?

Accepted Answer

Frequency multiplier (FM)

Answer

The Frequency Multiplier (FM) in the NIOSH equation adjusts the Recommended Weight Limit based on lifts per minute and duration of lifting task.

(CIEE) Certified Industrial Ergonomic Evaluator Practice Test

(CIEE) Certified Industrial Ergonomic Evaluator Practice Test

CIEE Repetitive Motion & CTD Prevention 2