The initial measurement was carried out in the control shoes, so
far worn by the subjects, to establish baseline SEMG information.
Afterwards all subjects were equipped with the test shoes without
cushioning (dummy cushioning element). Subsequent to this first
investigation subjects had worn the test shoes to accomplish
habituation. Except for the second investigation, for which as a
precaution the habituation period was extended to five working
days to break in the new shoes, two working days in a row were
given for habituation. All investigations were executed at the end of
the working day. The order of the two remaining cushioning elements
(optimal and too soft) was randomized beforehand but
evenly distributed between subjects. After each investigation,
cushioning elements were exchanged for the next ones scheduled
and habituation was started again (Fig. 1). All measurements took
place at the subjects' place of work