Solution

Explanation:

To calculate the Lifting Index (LI) using the NIOSH Lifting Equation spreadsheet, we need to input the provided data into the appropriate fields and then use the equation to determine the LI value. Here's how to do it step by step:

Input Data:

• Load Weight (L): 40 pounds
• Load Constant (LC): 51 pounds (for a box without handles)
• Horizontal Location (H): 10 inches
• Vertical Location Origin (Vo): 36 inches
• Vertical Location Destination (Vd): 28 inches
• Asymmetry Angle (A): Assume minimal twisting (low angle, say 0 degrees)
• Lifting Duration: 4 hours
• Lifting Frequency (F): Once every 3 minutes
• Coupling (C): Good (1.00)

Calculate the Multiplier (M):

• H Multiplier: 40 inches (standard height)
• V Multiplier: Calculate Vo-Vd = 36 - 28 = 8 inches

Use the NIOSH Lifting Equation:

RWL = (51 / LC) * (40 / H) * (1 - (|20 - 25| / 40)) * (1 - (0 / 180)) * (4 / 0.75) * (1 / 3) * 1.00 * 1.00

where:

• 51 is the Load Constant
• LC is the Load Weight (40 pounds)
• H is the Horizontal Location (10 inches)
• Vo-Vd is the Vertical Travel Distance (8 inches)
• A is the Asymmetry Angle (0 degrees)
• Lifting Duration (4 hours)
• Lifting Frequency (Once every 3 minutes)
• Coupling (C) = 1.00 (Good)
• V Multiplier = 1.00

Calculate RWL:

RWL = (51 / 51) * (40 / 10) * (1 - (|20 - 25| / 40)) * (1 - (0 / 180)) * (4 / 0.75) * (1 / 3) * 1.00 * 1.00

RWL = (1) * (4) * (0.75) * (1) * (1.00) * (0.3333) * 1.00 * 1.00

RWL = 1 * 4 * 0.75 * 1 * 1.00 * 0.3333 * 1.00 * 1.00

RWL = 1 * 4 * 0.75 * 1 * 0.3333

RWL = 0.9999 * 4 * 0.75

RWL = 2.9998 lbs (approximately 3 lbs)

Calculate Lifting Index (LI):

LI = Load Weight (L) / Recommended Weight Limit (RWL)

LI = 40 / 3

LI 13.33

Since LI > 3, this lift may exceed the capabilities of safely performing the lift for nearly all workers. Redesign of the lifting task is recommended.

• Briefly explain why you selected each of the values you did to arrive at the final Lifting Index.
• What do the Lifting Index values indicate about the potential hazard of the task?
• What recommendations can you make about the task?