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   Lifting Tasks:
Female - Lifting Task Ending Below Knuckle Height (<28")
Male - Lifting Task Ending Below Knuckle Height (<31")
Female - Lifting Task Ending Between Knuckle Height (≥28") & Shoulder Height (≤53")
Male - Lifting Task Ending Between Knuckle Height (≥31") & Shoulder Height (≤57")
Female - Lifting Task Ending Above Shoulder Height (>53")
Male - Lifting Task Ending Above Shoulder Height (>57")
   Lowering Tasks:
Female - Lowering Task Beginning Below Knuckle Height (<28")
Male - Lowering Task Beginning Below Knuckle Height (<31")
Female - Lowering Task Beginning Between Knuckle Height (≥28") & Shoulder Height (≤53")
Male - Lowering Task Beginning Between Knuckle Height (≥31") & Shoulder Height (≤57")
Female - Lowering Task Beginning Above Shoulder Height (>53")
Male - Lowering Task Beginning Above Shoulder Height (>57")
   Pushing Tasks:
Female - Pushing Task Initial Forces
Male - Pushing Task Initial Forces
Female - Pushing Task Sustained Forces
Male - Pushing Task Sustained Forces
   Pulling Tasks:
Female - Pulling Task Initial Forces
Male - Pulling Task Initial Forces
Female - Pulling Task Sustained Forces
Male - Pulling Task Sustained Forces
   Carrying Tasks:
Female - Carrying Task
Male - Carrying Task
Instructions
Suppose you want to find the female population percentage for lifting tote pans. Your measurements include (see guidelines below):

          Tote pans weigh 29 pounds
          Hand distance away from body of 7 inches
          An initial hand height at start of 30 inches
          A hand height at end of task of 50 inches, and
          Tote pans are lifted once every 5 minutes

  • First you must select the correct “Table” from the Select Task menu. Since you are looking for female population percentages, select; Female - Lifting Task Ending Between Knuckle Height & Shoulder Height (≥28” and ≤53”).
  • Enter the Object Weight of 29 lb.
  • Select from the Lifting Distance pull down menu 20 inches.
  • Select from the Hand Distance pull down menu 7 inches.
  • Select from the Frequency - One Lift Every pull down menu 5 minutes.
  • Select Compute Population Percentage. This is the population percentage of female workers able to perform this task without overexertion or fatigue.
  • Many times measurements will lie in-between those values in the pull down menus e.g. Hand Distance, Frequency, Lifting, Lowering, Carrying Distance, and Hand Heights. If so, round off to the higher or lower value depending on whether the value is above or below the middle value of the measurements. For example, for same Female - Lifting Task Ending Between Knuckle Height & Shoulder Height (≥28” and ≤53”) task; for a measured Lift Distance of 16 inches than select 20 inches and for a measured Lift Distance of 14 inches then select 10 inches etc.
  • Liberty Mutual Tables is intended to be a flexible tool. If you would like to see the population percentage differences between a Lifting Distance of 20 inches and 10 inches then select one and then the other and Compute Population Percentage each time. Compare population percentage results. Same would be true for entering Object Weights any other measurements including Hand Distance. This is how What-If scenarios can be performed using Liberty Mutual Tables.
  • Hand Distance is the distance from the front of the body to the hands. (Note that this is a different measurement from the 1991 Revised NIOSH Lifting Guide). Hand Distance will normally be half the width of the object being handled unless the object is purposely held away from the body.
  • For Pushing and Pulling Tasks you will need to obtain a force gage or force measurement device and enter the initial force, in pounds, needed to start the object moving. Take several measurements and enter the highest value particularly when floor or wheel conditions are poor. For pushing tasks, you can measure the force by pulling. However, while the effect on the worker may be different between a push and pull, the measured force will be the same. Also obtain the sustained force measurement to keep the object moving. All measurements should be taken at an acceleration representative of the task as performed in the actual operating environment.

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