Ergonomics follows a very simple basic
model that derives from physics: When you impact a body with a certain stress, the body will react with a
corresponding strain. Since a standard method causes a
stress that is typical for this standard method, the strain as a reaction to
this typical stress situation should be typical, too.
The intensity of the strain, however, is
not the same. It depends on the worker: his personal attributes, his abilities
and his skills (together they form the capability for work). And
it varies due to the actual disposition and motivation (together called readiness
for work), and his health. If the strain overruns the permanent work
load, breaks are necessary for his personal recovery to avoid acute
or chronic damage.
We know that there are days when the
same job feels hard, and days when it feels much easier. So, for the same
individual the strain can differ. This partly depends on the health,
conditioning, tiredness, hunger and time of the day. We call these organic reasons
disposition.
