User interface > Tab "Results" > Ergonomics

The NIOSH sub-tab allows automatic evaluation of load handling operations using the NIOSH revised lifting equation (Waters et al., 1994). For evaluation, the load weight, as well as various execution conditions, such as pick-up and deposit height and distance, are considered. As a result, a lifting index can be output to assess the physical stress of the activity, as well as the recommended weight limit for the activity. The lifting index can be calculated as a risk assessment for individual activities (LI = Lifting Index) or as a composite for all activities of the worker (CLI = Composite Lifting Index). The risk assessment with associated recommended action for corresponding lifting index values can be seen in the following table:

Lifting Index Value	Risk Implication	Recommended Action
LI <= 1,0	Very low risk	No action for healthy working population necessary.
1,0 < LI <= 1,5	Low risk	Pay attention to low frequency/high load conditions and extreme postures. Consider efforts to reduce LI <= 1,0.
1,5 < LI <= 2,0	Moderate risk	Redesign tasks and workplace to reduce LI and follow up analysis to confirm effectiveness.
2,0 < LI <= 3,0	High risk	Redesign of the tasks is recommended with high priority.
LI > 3,0	Very high risk	Immediate redesign of the tasks is recommended with highest priority.

The NIOSH lifting equation should not be applied, when

…working with one hand.

…working for over 8 hours.

…working while seated or kneeling.

…working in a restricted work space.

…handling objects that are unstable (such as buckets or containers of liquids).

…the load is carried for more than 2 steps between picking up and placing.

…working while pushing or pulling.

…working with wheelbarrows or shovels.

…working with high speed motion (faster than about 76.2 cm/second).

…working with extremely hot or cold objects or in extreme temperatures.

...working with poor foot/floor coupling (high risk of a slip or fall).

…working with holding the load for more than 5 s.

…working with a horizontal distance of the lifted load further away than 63 cm from the midpoint between the ankles.

…working with a vertical distance of the load not higher than 175 cm above floor level.

…the asymmetric angle while lifting is above 135°.

…working above a maximum frequency that is dependent on the vertical location of the object and the duration of lifting. In emaWD this is automatically calculated and an exceedance of the maximum frequency will result in an irrelevant load case with a corresponding warning message.