The use of vibro-tactile arrays to inform pilots about orientation (Rupert, 2000) has prompted investigations of their use in providing patients with supplementary information which may aid balancing (Wall et al. 2003). Published studies have used steady-state balancing which does not reveal whether vibration feedback can be fast enough to cue a saving reaction. Accordingly, we evaluated vibratory feedback in cueing a single step balancing response to a transient perturbation. Human subjects stood facing longitudinally on a moving walkway. Body movements were transduced with gyroscopes (angular velocity), accelerometers and Fastrak® position transducers. Vibration was 100 ms bursts from mobile phone vibrators triggered by body movement. (i) The locus of vibration giving the shortest latency step response was determined by comparing the latencies of step responses to bursts of vibration applied to the forehead vs the xiphoid process of the sternum. Subjects were instructed to step as soon as they felt the vibration. In 7 subjects mean reaction times, from vibration to step initiation, were significantly lower for the head, 176±36 ms, compared with the trunk, 225±54 ms (t test, P<0.05). (ii) The part of the body giving the earliest signal of instability with balance challenge was determined by destabilising posture with unpredictable accelerations (4 m s^-2) of the walkway, forwards or backwards with trapezoidal velocity profiles peak 1.5 m s^-1 or 1.1 m s^-1. Subjects had to respond with a rapid step to avoid toppling. Mounting the various transducers on ankle, hip, shoulder and head it was found that the gyroscope placed on the lower part of the thigh, just above the knee, gave the earliest (48+11 ms) least ambiguous signal of the perturbation and then only to backwards walkway motions. (iii) Thereafter, the combination of signals from the thigh to trigger vibration on the forehead was used to determine whether vibratory cues could enhance the stepping response to unpredictable backwards walkway translation. The trigger for vibration was given when the gyro signal reached a subject-dependent threshold of passive leg tilt. Four normal, age-matched subjects and 3 patients with bilateral vestibular loss were tested. Reaction times were measured as latency between the onset of translation and the time for the gyro signal to reach a zero crossing signifying that a step had been initiated. There was no difference between normal reaction times with and without vibration cueing feedback 284 (SD±80) ms and 274 (±40) ms. Patients also had similar reactions, 283 (±20) ms with and 290 (±50) ms without vibration. These preliminary results suggest that vibro-tactile feedback triggered from the bodys own instability may be ineffective in shortening the latency of a step response in either normal subjects or patients with significant disorders of balance.