CEA Musculoskeletal Disorder Prevention 2 — Questions and Answers
Question 1: Which of the following best describes the 'dose-response relationship' in MSD risk assessment?
- Greater exposure to a risk factor increases the likelihood of developing an MSD (Correct answer)
- A single high-force exertion is always more harmful than repeated low-force exertions
- MSD symptoms appear immediately after the causative exposure
- The relationship between posture and injury is linear and predictable
Correct answer: Greater exposure to a risk factor increases the likelihood of developing an MSD
The dose-response relationship means that as exposure to ergonomic risk factors (force, repetition, awkward posture) increases, the probability and severity of MSDs increase.
Question 2: A warehouse worker reports tingling and numbness in the thumb, index, and middle fingers that worsens at night. Which MSD is most consistent with these symptoms?
- De Quervain's tenosynovitis
- Carpal tunnel syndrome (Correct answer)
- Cubital tunnel syndrome
- Raynaud's phenomenon
Correct answer: Carpal tunnel syndrome
Carpal tunnel syndrome compresses the median nerve, causing tingling and numbness in the thumb, index, and middle fingers, often worse at night.
Question 3: Which administrative control is MOST effective at reducing MSD risk from highly repetitive tasks?
- Posting warning signs near high-risk workstations
- Implementing job rotation among tasks with different muscle group demands (Correct answer)
- Requiring workers to wear compression gloves
- Increasing the pace to reduce total shift duration
Correct answer: Implementing job rotation among tasks with different muscle group demands
Job rotation among tasks that use different muscle groups reduces cumulative loading on any single tissue, lowering MSD risk.
Question 4: The concept of 'tissue tolerance' in ergonomics refers to:
- A worker's psychological ability to tolerate discomfort
- The maximum load a biological tissue can sustain before damage occurs (Correct answer)
- OSHA's permissible exposure limits for biomechanical stressors
- The duration a worker can maintain a static posture safely
Correct answer: The maximum load a biological tissue can sustain before damage occurs
Tissue tolerance is the threshold load beyond which musculoskeletal tissues (tendons, muscles, discs) sustain micro-damage that can accumulate into an MSD.
Question 5: In the NIOSH lifting equation, what does the 'Asymmetry Multiplier (AM)' account for?
- The horizontal distance of the load from the body's midline
- Twisting of the torso away from the sagittal plane during lifting (Correct answer)
- The height at which the lift originates
- The frequency of lifts per minute
Correct answer: Twisting of the torso away from the sagittal plane during lifting
The Asymmetry Multiplier penalizes lifting tasks that require trunk rotation, as twisting significantly increases spinal loading and disc injury risk.
Question 6: Which of the following work scenarios presents the HIGHEST risk of developing lateral epicondylitis (tennis elbow)?
- Repetitive wrist flexion combined with gripping tools tightly
- Sustained elbow flexion while using a mouse
- Frequent pinching tasks with the thumb and index finger
- Repeated pronation and wrist extension while using hand tools (Correct answer)
Correct answer: Repeated pronation and wrist extension while using hand tools
Lateral epicondylitis results from overloading the wrist extensor tendons, commonly caused by repetitive forearm pronation and wrist extension with gripping.
Question 7: During an ergonomic intervention evaluation, what does the term 'leading indicator' refer to?
- The number of OSHA recordable MSD injuries in the past year
- A proactive measure such as near-miss reports or discomfort survey scores that predict future injury risk (Correct answer)
- Workers' compensation costs associated with MSDs
- Days away from work due to musculoskeletal conditions
Correct answer: A proactive measure such as near-miss reports or discomfort survey scores that predict future injury risk
Leading indicators are proactive, predictive metrics (e.g., discomfort surveys, near-miss reports) that signal MSD risk before injuries occur, unlike lagging indicators which record past events.
CEA Musculoskeletal Disorder Prevention 2
Which of the following best describes the 'dose-response relationship' in MSD risk assessment?