Civil Engineering Reference
In-Depth Information
The measurement of these horizontal distances should not interfere with the work being done by the
employee. The ergonomist who measures these distances should stand close enough to the individual to
get accurate readings, but far enough away to not disturb the work. It is important that the individual be
able to move naturally at the job site. A monitored individual being crowded by an investigator will move
differently, change his or her trunk motions, and give erroneous information via the iLMM concerning
the required activities of the task.
49.9 Setting Up the iLMM for Data Collection
After the job has been selected, the tasks identified, and basic work place information has been gathered,
the data collection process can begin. The proper iLMM size needs to be chosen and prepared for use.
This process is depicted in a flow chart (Figure 49.7) and is described next.
49.9.1 Selecting the Correct iLMM Size
The standing height of the individual to be monitored is usually the best indicator of which iLMM size to
use. It is important that the top of the iLMM moves easily within the slide plate that is attached to the
shoulder harness. The iLMM should not separate from the slide plate when the individual performs the
activity to be monitored (indicating that too small of a size is being used), nor should the T-sections of
the iLMMmove within the slide plate (signifying that too large of a size has been selected). Thus, the type
of trunk movement required of the job also must be considered when choosing the appropriate iLMM
size, especially that involving extreme forward flexion.
49.9.2 Adjusting the iLMM
Each iLMM is individually calibrated during manufacturing, and there is a specific position designated as
its “neutral” position. During normal usage, this position may change slightly and must be readjusted
(using the software) before every subsequent use. After sizing the iLMM, it must be secured in its
zero-plate, and its voltage offsets adjusted using the supplied iLMM software. The three traces shown
in the software (representing the three cardinal planes of motion) should show realistic position
values. Every iLMM must be adjusted in this manner before it is placed on an individual. This readies
the iLMM for data collection.
Select / Adjust iLMM Size
XS, S, M, or L
Adjust iLMM Offsets
Place Shoulder Harness on
Individual; Adjust Straps
Remove iLMM from Case
Place iLMM on Individual;
Adjust Waist, Shoulder Straps
Attach iLMM to Waist Belt
FIGURE 49.7
Flow chart of the iLMM setup procedure.
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