This document contains information from an ergonomic assessment of various manual material handling tasks. It lists task variables determined for four lifting tasks including vertical location, frequency, horizontal distance, distance of lift, and weight lifted. It also lists variables for four carrying tasks and four pushing/pulling tasks, including carry/push/pull point, frequency, distance, and initial and sustained forces. The tasks involved lifting, carrying and moving objects of various weights, distances and frequencies.

2. Liberty Mutual MMH “Snook Tables”

3. Links:
Ergonomics Plus Calculator
Bernard’s Adapted Tables

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6. • Vertical Location
• Floor to Knuckle (below 29”)
• Knuckle to Shoulder (29 - 54”)
• Above Shoulder (above 54”)
• Frequency
• 1 action/8 hours
• 1 action/30 minutes
• 1 action/5 minutes
• 1 action/2 minutes
• 1 action/ 1 minute
• 1 action/14 seconds
• 1 action/9 seconds
• 1 action/5 seconds
• Horizontal Distance
• 7”
• 10”
• 15”
• Distance of Lift
• 10”
• 20”
• 30”

7. Task Variables determined by the assessment:
• Vertical Location – floor to knuckle lift (below 29”)
• Frequency - average of 1 lift every 2 minutes
• Horizontal Distance – 10” (front of body to mid-line of hands)
• Distance of Lift – 30” (lifts from height of 4” to 32”= 28”)
• Weight of Object – 35 lbs.

8. Task Variables determined by the assessment:
• Vertical Location – Above Shoulder (above 54”)
• Frequency - 1 action every 5 minutes (12 actions/hour)
• Horizontal Distance – 10” (front of body to mid-line of hands)
• Distance of Lift – 30” (lifts from height of 28” to 60”= 32”)
• Weight of Object – 28 lbs.

9. Task Variables determined by the assessment:
• Vertical Location – Knuckle to Shoulder (29 - 54”)
• Frequency - 1 action every 5 minutes (12 actions/hour)
• Horizontal Distance – 15”
• Distance of Lift – 20” (lowers from height of 49.5” to 31”= 18.5”)
Weight of Object – 25 lbs.

10. Task Variables determined by the assessment:
• Vertical Location – Knuckle to Shoulder (29 - 54”)
• Frequency - 1 action every 30 minutes (2 actions/hour)
• Horizontal Distance – 7”
• Distance of Lift – 10”
• Weight of Object – 30 lbs.

12. • Carry Point (Vertical Location)
• Waist height (elbows bent)
• Below Waist Height (elbows straight)
• Frequency
• 1 action/8 hours
• 1 action/30 minutes
• 1 action/5 minutes
• 1 action/2 minutes
• 1 action/ 1 minute
• 1 action/20 seconds
• 1 action/10 seconds
• Carry Distance
• 7’
• 14’
• 27’

13. Task Variables determined by the assessment:
• Carry Point –Waist Height
• Frequency - 1 carry every 2 minutes (30 actions/hour)
• Carry Distance – 27’
• Weight of Object = 52 lbs.

14. Task Variables determined by the assessment:
• Carry Point –Waist Height
• Frequency - 1 carry every minute
• Carry Distance – 27’
• Weight of Object = 40 lbs.

16. • Push/Pull Distance
• 7’
• 24’
• 48’
• 97’
• 145’
• 194’
• Push/Pull Point (Vertical
Location)
• High (hands about 55”)
• Middle (hands about 36”)
• Low (hands about 24”)
• Frequency
• 1 action/8 hours
• 1 action/30 minutes
• 1 action/5 minutes
• 1 action/2 minutes
• 1 action/1 minute
• 1 action/30 seconds
• 1 action/15 seconds
• 1 action/12 seconds
• 1 action/6 seconds
• Force Measurement
• Initial Force
• Sustained Force

19. Task Variables determined by the assessment:
• Pull Point – Middle
• Frequency - 1 pull per 5 minutes
• Pull Distance – 97’
• Initial Force = 53 lbs.
• Sustained Force = 25 lbs.

20. Task Variables determined by the assessment:
• Pull Point – Low
• Frequency - 1 pull per 2 minutes
• Pull Distance – 24’
• Initial Force = 75 lbs.
• Sustained Force = 34 lbs.

21. Task Variables determined by the assessment:
• Push Point – Middle
• Frequency - 1 pull per 1 minute
• Push Distance – 97’
• Initial Force = 24 lbs.
• Sustained Force = 15 lbs.

22. Task Variables determined by the assessment:
• Pull Point – Middle
• Frequency - 1 pull per 30 minutes
• Pull Distance – 145’
• Initial Force = 35 lbs.
• Sustained Force = 14 lbs.