The assessment is basically conducted for manual handling tasks and must be related to one working day. If load weights and/or postures change within an individual activity average values must be formed. If a number of manual handling tasks with substantially different load manipulations arise within the overall activity, they must be estimated and documented separately.

The following 3 steps are necessary in the assessment:
1. Determination of the time rating points,
2. Determination of the rating points for the key indicators and
3. Evaluation.

In the determination of the rating points it is basically permitted to form intermediate steps (interpolation). A frequency of 40 produces the time rating point 3, for example. The only exception is the effective load of equal or above 40 kg for a man and 25 kg for a women. These loads uncompromisingly yield a load rating of 25.

The Key Indicator Method worksheet for activities involving Lifting, Holding, Carrying may be downloaded here:

 Interactive KIM-Worksheet for activities involving Lifting, Holding, Carrying (file, 227 kB)
This interactive worksheet allows to fill the form on a computer and automatically calculates the activity-related risk score. The result may be saved on the computer.

Further useful documents related to this method:

 Printable KIM-Worksheet for activities involving Lifting, Holding, Carrying (file, 109 kB)
This worksheet is for use without a computer for paper-pencil assessment.

 Short lesson with examples and Answers to frequently asked Questions (file, 1968 kB)
This short lesson provides useful information for using KIM in practice, gives examples for assessment and gives answeres to frequently asked questions.

Caution!
This procedure only serves as an orienting assessment of the working conditions for lifting and carrying loads. Nevertheless good knowledge of the manual handling task being assessed is absolutely essential when determining the time rating, load rating, posture rating and the rating of the working conditions. If this knowledge is not present no assessment may be made. Rough estimates or suppositions lead to incorrect results.

1st step: Determination of the Time Rating Points

The time rating points are determined with reference to the table separately for three possible forms of load handling:

• For manual handling tasks characterised by the regular repetition of short lifting, lowering or displacement operations, the number of operations is a determinant for the time rating points.
  
• For manual handling tasks characterised by the holding of loads, the total duration of the holding is taken.(total duration = number of holding operations x duration of a single holding operation)
  
• For manual handling tasks characterised by the carrying of a load, the total distance covered with the load is taken. An average speed when walking of 4 km/h ≈ 1 m/s is assumed.
  

2nd step: Determination of the Rating Points of Load, Posture and Working conditions

2.1 Load weight

• The load rating points are determined with reference to the table separately for men and women.
  
• If, in the course of the manual handling task being assessed, different loads are handled, an average value may be formed where the greatest single load for men does not exceed 40 kg and for women 25 kg. For comparison purposes peak load values can also be used. Then, however, the reduced frequency of these peaks must be taken as a basis, and on no account the total frequency.
  
• In the case of lifting/holding/carrying/setting-down activities the effective load must be taken. The effective load mass here is the weight force which the employee actually has to cancel out. The load is therefore not always equal to the weight of the object. When a box is tilted, only about 50 % of the weight of the box acts.
  
• When loads are being pushed and pulled a separate assessment is necessary.
  

2.2 Posture

The rating points of posture are determined with reference to the pictograms in the table. The characteristic postures during the handling of loads must be used for the individual activity. If different postures are adopted as work progresses, an average value can be formed from the posture rating points for the manual handling task being assessed.

2.3 Working conditions

To determine rating points of the working conditions, the working conditions that predominate most of the time must be used. Occasional discomfort which has no safety significance will not be taken into account. Safety-relevant indicators must be documented in the text box "Check of the workplace for other reasons".

3rd step: Evaluation

Each task is evaluated on the basis of an activity-related risk score (calculation by addition of the rating points of the key indicators and multiplication with the time rating points).

• The basis for evaluation comprises biomechanical mechanisms of action combined with dose models. Account is taken here of the fact that the internal strain on the lower spine depends to a crucial extent on the extent to which the trunk is leaning forward and on the load weight and that it increases with increasing load duration and/or frequency, side bending and/or twisting.
  
• Summarised evaluations are difficult with a number of manual handling tasks because they go beyond the informative scope of this orientation analysis. They normally require more extensive work analysis procedures to obtain a risk assessment.
  
• Design needs that can be concluded
  From this risk estimate there is immediate evidence of design needs and approaches. Basically the causes of high rating points must be eliminated. Specifically these are organisational regulations in the case of high time rating points, reduction of the load weight or the use of lifting aids in the case of high load rating points or the improvement of ergonomic conditions in the case of high posture rating points.