PAS Workplace Ergonomic Interventions 3 — Questions and Answers
Question 1: A data entry specialist complains of numbness in the 4th and 5th fingers. The MOST likely ergonomic cause is:
- Resting the medial elbow on a hard desk edge compressing the ulnar nerve (Correct answer)
- Excessive keyboard tilt causing radial nerve stretch
- Monitor too far away causing forward head posture
- Chair backrest angled too far forward increasing thoracic kyphosis
Correct answer: Resting the medial elbow on a hard desk edge compressing the ulnar nerve
Hard-edge elbow resting compresses the ulnar nerve at the cubital tunnel, producing numbness in the ring and little fingers.
Question 2: When evaluating a warehouse picker for shoulder impingement risk, which overhead reaching threshold is most clinically significant?
- Sustained shoulder abduction or flexion exceeding 60° for more than 2 hours per shift (Correct answer)
- Any reaching above elbow height for more than 4 hours per shift
- Lifting objects weighing over 10 lbs with elbow extended
- Reaching across midline more than 20 times per hour
Correct answer: Sustained shoulder abduction or flexion exceeding 60° for more than 2 hours per shift
Sustained shoulder elevation beyond 60° narrows the subacromial space and is a primary ergonomic risk factor for impingement.
Question 3: For a sit-stand desk program to effectively reduce lumbar loading, the transition guideline most supported by evidence is:
- Alternating 30–45 minutes seated with 15–20 minutes standing throughout the day (Correct answer)
- Standing for the first 4 hours then sitting for the remainder of the shift
- Sitting 80% and standing 20% to avoid fatigue
- Alternating every 10 minutes to maximize disc nutrition
Correct answer: Alternating 30–45 minutes seated with 15–20 minutes standing throughout the day
30–45 minute seated intervals followed by 15–20 minute standing periods reduce cumulative spinal loading while preventing lower extremity fatigue.
Question 4: A PAS practitioner identifies that a grocery cashier's scanning motion requires 30° of repetitive wrist ulnar deviation. The BEST ergonomic fix is:
- Repositioning the scanner so items move toward the cashier rather than sweeping across the body (Correct answer)
- Teaching the cashier to grip the scanner with the non-dominant hand
- Providing a wrist brace to limit total range of motion
- Adding a 5-minute break after every 60 scanning repetitions
Correct answer: Repositioning the scanner so items move toward the cashier rather than sweeping across the body
Redesigning the task motion path eliminates the ulnar deviation pattern at its source rather than compensating for it.
Question 5: Which assessment tool is MOST appropriate for quantifying cumulative ergonomic exposure across multiple tasks in a workday for a PAS client?
- Rapid Entire Body Assessment (REBA) applied to each task with time-weighted averaging (Correct answer)
- Single-point Visual Analog Scale rating at end of shift
- Grip strength dynamometry before and after shift
- Static postural photography at one point in time
Correct answer: Rapid Entire Body Assessment (REBA) applied to each task with time-weighted averaging
REBA captures whole-body posture across tasks and time-weighting aggregates cumulative exposure, providing a comprehensive risk picture.
Question 6: A seamstress develops de Quervain's tenosynovitis. The ergonomic intervention with the highest priority is:
- Repositioning fabric so pinching occurs with the thumb in neutral rather than in full extension/abduction (Correct answer)
- Providing a thimble to reduce pinch force requirement
- Applying ice to the radial wrist after each work session
- Scheduling sewing tasks in 15-minute blocks with 5-minute rest
Correct answer: Repositioning fabric so pinching occurs with the thumb in neutral rather than in full extension/abduction
De Quervain's is caused by repetitive abduction-extension of the thumb; repositioning the task to keep the thumb neutral eliminates the causative motion.
Question 7: Which lighting ergonomic factor is most associated with forward head posture at computer workstations?
- Screen glare causing the user to lean forward to reduce reflection (Correct answer)
- Insufficient ambient light requiring larger font size
- Overhead fluorescent flicker increasing eye strain
- Desk lamp positioned to the dominant hand side
Correct answer: Screen glare causing the user to lean forward to reduce reflection
Glare on the monitor surface prompts workers to thrust the head forward to view the screen from a different angle, compounding cervical strain.
PAS Workplace Ergonomic Interventions 3
A data entry specialist complains of numbness in the 4th and 5th fingers.
The MOST likely ergonomic cause is: