Ergonomics - Atlas Copco

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Introduction
A basic ergonomic principle when design-
ing a hand-held power tool is that operation
should be easy and involve no risk of dam-
age to the health of the operator or to the
immediate environment. A poorly designed
tool poses a number of potential risks.
The wrong type of handle may have been
chosen in relation to the workstation and/or
the task to be performed. This can lead to
awkward working postures and reduced op-
erator capacity in terms of muscular strength.
The physical characteristics of the
operator may not have been fully taken
into consideration. Thus, the size or shape
of the hand tool may cause excessive local
pressures to be applied to the blood vessels
and nerves of the hand, resulting in mus-
culoskeletal symptoms. These factors are
discussed in the chapter entitled Handle
Design.
The undeniable advantages of powerful
hand tools in many industrial situations
may sometimes be a distinct disadvantage
for the operators. The reactive force or
torque generated by such powerful tools
may well be beyond the limit that an op-
erator can withstand without sustaining
physiological injury.
Holding heavy tools subjects the up-
per extremities to continuous load and
applies static load to certain musculoskel-
etal structures. The vibration caused by a
conventional percussive tool may be very
uncomfortable for the operator and cause
damage to the neuro-vascular system of the
hand in the form of, for example, white fin-
ger syndrome. The chapters External Load,
Weight, Shock Reaction, and Vibration cover
these factors.
The motors of hand-held tools may cause
contact surfaces to become extremely hot or
cold. Noise, dust and oil not only influence
the health of the operator but also the work-
ing environment. Ergonomic considerations
relating to these risk factors are described
in the chapters Temperature, Noise and
Dust and Oil.
As ergonomics is still a relatively young
science, many of the risk factors mentioned
above require further study in order to
determine the quantitative relationship
between operator exposure and the sub-
sequent effect on the health of the person
concerned.
The evaluation method presented in this
chapter can be applied to find the best tool