Article

The aim of this study was to know whether subjects involved in a locomotion
experiment modified their running pattern when made aware that data were being
collected, and of the specific parameters studied.
We used standardised actual
and deceptive messages to induce increasing levels of awareness, and analysed
subjects' running pattern on a treadmill dynamometer, using lower limb stiffness
as the key mechanical parameter. The five levels of awareness were: (1) subjects
thought no sampling was performed, (2) they knew a sampling was about to take
place, without knowing the parameter studied, (3) they knew this sampling was in
progress, (4) they knew that sampling of lower limb stiffness was about to take
place, and (5) they knew this sampling was in progress. Subjects' running pattern
significantly changed with the increasing level of information given, with a
higher stiffness and step frequency, a reduced contact time and a lower change in
leg length during contact. Post hoc tests showed that subjects changed their
running pattern when knowing (i) that a sampling was performed and (ii) the
mechanical parameter studied. These preliminary results suggest that experimental
designs in locomotion protocols should take this potential "sampling" effect into
account, whenever possible.

Langue : ANGLAIS