  Balance and gait disorders are the second leading cause of falls, which,
along with consequent injuries, are reported as major public health problems
all over the world. For patients who do not require mechanical support,
vibrotactile feedback interfaces have proven to be a successful approach in
restoring balance. Most of the existing strategies assess trunk or head tilt
and velocity or plantar forces, and are limited to the analysis of stance. On
the other hand, central to balance control is the need to maintain the body's
centre of pressure (CoP) within feasible limits of the support polygon (SP), as
in standing, or on track to a new SP, as in walking. Hence, this paper proposes
an exploratory study to investigate whether vibrotactile feedback can be
employed to lead human CoP during walking. The ErgoTac-Belt vibrotactile device
is introduced to instruct the users about the direction to take, both in the
antero-posterior and medio-lateral axes. An anticipatory strategy is adopted
here, to give the users enough time to react to the stimuli. Experiments on ten
healthy subjects demonstrated the promising capability of the proposed device
to guide the users' CoP along a predefined reference path, with similar
performance as the one achieved with visual feedback. Future developments will
investigate our strategy and device in guiding the CoP of elderly or
individuals with vestibular impairments, who may not be aware of or, able to
figure out, a safe and ergonomic CoP path.
