Ergonomics - Atlas Copco

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The arm sling as a preventive measure
When there is a risk of prolonged static
load on the shoulder region and the work is
performed within a wider radius so that the
use of arm-rests is not feasible, arm slings
are sometimes used. The lift force of an
arm sling should be individually adjusted
to about 20% of the total arm weight (about
5% of the total body weight). The introduc-
tion of arm slings should not interfere with
the task being performed. If this is the case,
other alternatives should be explored.
Although more beneficial for operators
with musculoskeletal symptoms, the arm
sling should generally be regarded as a
preventive measure rather than as an aid
to rehabilitation.
Weight balancers reduce fatigue
The weight of a hand tool, particularly
a power tool, imposes limitations on the
length of time that an operator can per-
form the task, while reducing the degree of
precision that the operator can achieve. In
general, any tool weighing more than 2.5 kg
that has to be operated while supported by
the arms, and that has to be held out from
the body in an awkward posture should be
provided with a “weight balancer”.
Arm slings compensate for the weight of the arms,
and reduce tension in the shoulder-neck area.