The authors used a vertical force platform fitted with 4 pressure gauges (Societe Toennies). The static regime provides the statokinesigram, the lateral and sagittal stabilograms and their Fourier transformations. Information is collected with the eyes open and closed, thereby allowing the Romberg quotient to be determined. In the dynamic regime, the platform unexpectedly tilts to a toes-up position (4 degrees at a rate of 50 degrees/s). The activity of the tibialis anterior and soleus muscles is recorded by integrated electromyography. The early soleal response, provoked by the myostatic reflex, is followed by later responses due to the vestibulo-spinal reflex. These various parameters were recorded in young athletes and the obtained tracings are commented on.