Biomedical Engineering Reference
In-Depth Information
Similarly, training should encourage the construction of a gestural
solution that takes into account these various forms of variability. One
can only be sceptical, at this point, regarding training programs that focus
on the 'one best gesture' and 'one best posture', which tend to reduce the
scope of the solutions implemented by operators and to decontextual-
ize the solutions constructed in a specific context. On the contrary, these
should be designed based on the analysis of gestural variability and on
the identification of gestural know-how, in order to allow trainees to
construct their own gestural solutions based on those of more experi-
enced operators.
Here is an example. In a company from the food processing indus-
try, the design of a duck cutting line provides some room for manoeuvre,
notably to organize the training of new employees on the line without
disrupting production (Coutarel et al., 2003). An intervention carried out
5 years after the implementation of this line made it possible to study
in greater detail how operators are trained to the gestures of cutting
(Dugué et al., 2010). An experienced worker, who guides the operator in
real time during the production phase, supervises this training program.
The trainer is acting in a doubloon. He demonstrates the gesture, divides
the action into more elementary operations so that the apprentice can
learn step by step, and examines and retains what the apprentice is not
doing. This is a contextual training to gestures, where cutting gestures
are apprehended in all of their complexity: in terms of effectiveness, effi-
ciency and health. The trainer demonstrates gestures, accompanies the
gesture of the apprentice, and emphasizes the quality of the cut prod-
uct and the strength that should be exerted on the knife. A few hints are
given, allowing the apprentice to strain less and to do high-quality work
while holding the pace. For example, in order to cut the leg of a duck, part
of the cutting is done 'blind', in the sense that the operator cannot see the
joint. The trainer explains, by demonstrating and guiding the knife into
the joint, that this joint is shaped like an S, and that one should follow this
shape to cut the leg well (and not damage the bone), not to strain on the
tough parts of the bone, and not to waste time by jamming the knife into
these tough parts. The training places an emphasis on the sensation of
using the knife when following the S-shape, and when the blade encoun-
ters obstacles when reaching the tougher parts. Some other knowledge
is also imparted, regarding topics such as the angle of the blade against
the flesh, the depth the knife should reach in the flesh, etc. The diversity
of sensory information that operators rely on can be used as an input for
training programs. This sensory information is essential for carrying out
a gesture. And often, this information and its role in the gesture are under-
estimated - as evidenced by training programs that are mostly based on a
purely biomechanical view of gestures. Furthermore, the learner is imme-
diately confronted with the variability of the situation. The knowledge
