CIEE Manual Material Handling Assessment 2 — Questions and Answers
Question 1: Which NIOSH equation variable accounts for the horizontal distance between the worker's hands and the midpoint of the ankles at the origin of the lift?
- Vertical multiplier (VM)
- Horizontal multiplier (HM) (Correct answer)
- Asymmetric multiplier (AM)
- Frequency multiplier (FM)
Correct answer: Horizontal multiplier (HM)
The horizontal multiplier (HM) penalizes lifts where load is far from the body, calculated as 25/H where H is the horizontal distance in cm.
Question 2: In the NIOSH lifting equation, what is the Recommended Weight Limit (RWL) when the Lifting Index (LI) equals 1.0?
- RWL equals the actual load weight (Correct answer)
- RWL equals zero
- RWL equals 23 kg
- RWL is undefined
Correct answer: RWL equals the actual load weight
An LI of 1.0 means the actual load weight exactly equals the RWL, placing the task at the boundary of acceptable risk.
Question 3: Which factor distinguishes a 'significant control' condition at the destination in the revised NIOSH lifting equation?
- The worker must twist more than 45 degrees at destination
- The worker must carefully position or guide the load at the destination (Correct answer)
- The destination is more than 30 cm lower than the origin
- The load weighs more than 16 kg at the destination
Correct answer: The worker must carefully position or guide the load at the destination
Significant control at destination requires the evaluator to calculate a separate RWL for both origin and destination, using the lower value.
Question 4: A worker lifts 12 kg boxes from floor level (V=0) to a shelf at 150 cm. Compared to a lift where V=75 cm, the vertical multiplier (VM) at the origin is:
- Higher, because floor-level lifts are biomechanically easier
- Lower, because floor-level origin increases lumbar stress (Correct answer)
- The same, because VM only applies at the destination
- Higher, because V=0 maximizes the multiplier formula
Correct answer: Lower, because floor-level origin increases lumbar stress
VM = 1 – (0.003 × |V – 75|), so V=0 gives VM = 1 – (0.003 × 75) = 0.775, which is lower than VM = 1.0 at V=75 cm.
Question 5: When assessing push/pull tasks using the Snook and Ciriello tables, which parameter most directly determines the acceptable force limit for sustained pushing?
- Body weight of the 50th percentile worker
- Distance of the push task and frequency of exertion (Correct answer)
- Coefficient of friction between shoes and floor
- Height of the worker's center of gravity
Correct answer: Distance of the push task and frequency of exertion
Snook and Ciriello tables are indexed by push/pull distance, frequency, and the height at which force is applied to determine acceptable force limits.
Question 6: Which ergonomic intervention most effectively reduces lumbar compression during a two-handed symmetric lift from below knuckle height?
- Installing anti-fatigue mats at the workstation
- Raising the origin height to approximately knuckle level (Correct answer)
- Providing a weight belt for the worker
- Limiting shift duration to 6 hours
Correct answer: Raising the origin height to approximately knuckle level
Raising the origin to knuckle height minimizes trunk flexion and reduces lumbar compressive forces by improving the lift geometry.
Question 7: In a team lift scenario involving two workers, how should the NIOSH equation be applied to determine task acceptability?
- Divide the load weight by two and apply standard single-person RWL
- Apply the full load weight against each worker's individual RWL calculated for their specific body position (Correct answer)
- Double the load constant to 46 kg before calculating RWL
- Use only the frequency multiplier adjustment for team lifts
Correct answer: Apply the full load weight against each worker's individual RWL calculated for their specific body position
Each worker's individual posture and position may differ, so each must have a separate RWL calculated; the actual load each handles should reflect their share but the posture inputs are person-specific.
CIEE Manual Material Handling Assessment 2
Which NIOSH equation variable accounts for the horizontal distance between the worker's hands and the midpoint of the ankles at the origin of the lift?