13.4 Weight, frequency, and coupling

In addition to the origin and destination positions, each lifting task must be characterized by variables describing the load handled and the exposure conditions. These variables are entered in the Task Settings window, as shown in Figure 68.

The load weight is the actual weight handled by the worker. This value is subsequently compared with the Recommended Weight Limit calculated by the system. Therefore, the entered weight does not change the RWL; instead, it is used directly to calculate the Lifting Index by relating the actual load to the recommended limit for the task conditions.

Frequency, F, is the average number of lifts per minute for the task. When the entered frequency falls between two NIOSH tabulated values, Ergoniza Intelligent obtains the FM through linear interpolation. The FM is calculated for each duration category required by the evaluation blocks and takes the load's vertical height into account. The same task can therefore have different FM, RWL, and LI values depending on whether it is evaluated in a short-, moderate-, or long-duration block.

Coupling quality can be defined independently at the origin and destination as Good, Fair, or Poor. Together with the load's vertical height, this classification determines the Coupling Multiplier (CM) at each endpoint. A less favorable coupling reduces the RWL.

The handling method must also be specified, particularly whether the load is handled with one hand or both hands. This information is necessary to represent the analyzed situation accurately and to interpret the results in relation to the actual task.