SSH Ergonomics & Musculoskeletal Disorder Prevention 1 ā Questions and Answers
Question 1: Which of the following is the MOST common work-related musculoskeletal disorder (WMSD) reported in U.S. workplaces?
- Carpal tunnel syndrome
- Rotator cuff tendinitis
- Low back pain (Correct answer)
- Lateral epicondylitis
Correct answer: Low back pain
Low back pain is the most prevalent work-related musculoskeletal disorder, accounting for the greatest number of lost workdays and workers' compensation costs in the U.S.
Question 2: According to NIOSH, which of the following is NOT one of the primary ergonomic risk factors for musculoskeletal disorders?
- Repetitive motion
- Awkward posture
- Contact stress
- High ambient temperature (Correct answer)
Correct answer: High ambient temperature
NIOSH identifies repetitive motion, awkward posture, contact stress, forceful exertion, vibration, and static posture as primary ergonomic risk factors; high ambient temperature is a thermal hazard, not a primary MSD risk factor.
Question 3: The Revised NIOSH Lifting Equation recommends a Recommended Weight Limit (RWL) for a two-handed manual lift. What is the load constant (LC) used as the starting point in this equation?
- 23 kg (51 lbs) (Correct answer)
- 16 kg (35 lbs)
- 30 kg (66 lbs)
- 20 kg (44 lbs)
Correct answer: 23 kg (51 lbs)
The NIOSH Lifting Equation uses a load constant of 23 kg (51 lbs), which represents the maximum recommended weight under ideal lifting conditions.
Question 4: A Lifting Index (LI) value greater than what threshold indicates a significant risk of musculoskeletal injury according to the NIOSH Lifting Equation?
- LI > 1.0 (Correct answer)
- LI > 2.0
- LI > 3.0
- LI > 0.5
Correct answer: LI > 1.0
An LI greater than 1.0 indicates that the lifting task exceeds the recommended weight limit, signifying a significant risk of musculoskeletal injury for some workers.
Question 5: Which type of ergonomic intervention involves modifying the workstation, tools, or equipment to reduce MSD risk?
- Administrative control
- Engineering control (Correct answer)
- Personal protective equipment
- Behavioral modification
Correct answer: Engineering control
Engineering controls involve physical modifications to workstations, tools, or equipmentāsuch as adjustable desks or ergonomic hand toolsāand are preferred over administrative controls under the hierarchy of controls.
Question 6: Carpal tunnel syndrome is caused by compression of which nerve at the wrist?
- Ulnar nerve
- Radial nerve
- Median nerve (Correct answer)
- Axillary nerve
Correct answer: Median nerve
Carpal tunnel syndrome results from compression of the median nerve as it passes through the carpal tunnel in the wrist, causing pain, numbness, and tingling in the hand.
Question 7: Which ergonomic assessment tool uses observable risk factor categoriesāsuch as neck, shoulder, and wrist postureāand assigns action levels to prioritize interventions?
- REBA (Rapid Entire Body Assessment) (Correct answer)
- WISHA Caution Zone Checklist
- Snook Tables
- ACGIH TLV for Hand-Arm Vibration
Correct answer: REBA (Rapid Entire Body Assessment)
REBA (Rapid Entire Body Assessment) evaluates posture of the neck, trunk, upper and lower limbs, and assigns an action level score to guide the urgency of ergonomic intervention.
SSH Ergonomics & Musculoskeletal Disorder Prevention 1
Which of the following is the MOST common work-related musculoskeletal disorder (WMSD) reported in U.S. workplaces?