Аннотация:Capturing human movements and determining their features are often necessary in thedevelopment of devices worn by persons or used by them in daily work. In this regard, the problem ofdetecting the beginning of rotation seems to be relevant and has many applications in bionavigationand biomechanics. One of the main difficulties in these tasks isminimizing the delay in detecting themotion. In this paper the problem of detecting the head turn beginning by inertial sensors data fixedon it—three-axis accelerometer and CRS—is considered. The requirement to determine the headturn beginning appears when trying to solve the problem of supplementing vestibular informationunder special conditions, for example, to solve the problem of the vestibulo-sensory conflict thatoccurs in a state of weightlessness.