Push and Pull – Force Measurement Updates, Interpretation of Measurements and Modes, Peculiarities (Curves, Steps, Etc.). Multi-task Analysis

Abstract

Push and Pull measurement using conventional instruments such as mechanical dynamometers, does not allow to fully appreciate the peculiarities of a path with curves, gradients or variations in the terrain.

High-sampling digital dynamometers allow to accurately observe the performance of the force during push and pull activities.

It’s possible to identify:

• The Initial Force by recording the peak in the initial phase;

• The Sustained Force by recording the entire phase after the peak: in this case, the value should be processed as a 50th, 75th or 90th percentile of the sample of data recorded, because the percentile concept approximates the classical interpretation of the Sustained Force, according to proposed criteria by Stover H. Snook and Vincent M. Ciriello, authors of the benchmarks for the push and pull activities of the International Standard ISO 11228-2.

In various measurement experiences carried out in working environments such as urban waste management, hospital departments, or manufacturing departments, it has been observed that sustained force is not constant, but also varies rapidly. These variations are intrinsic to any handling activity, but introduce a further difficulty in defining the value of this factor.

During the shift operators are exposed to multiple handling tasks: it’s important to set up a multitask analysis push and pull activities.

Curves, steps and gradients introduce additional variables to the Multitask Analysis.

The analysis of the various situations allows to create a database of useful data to map the risk in advance.