Optical flow is of prime importance for the regulation of posture and locomotion. In adult subjects, it has been shown that directional effects of optical flow do change the velocity of locomotion as walkers slow down in an approaching flow (Fliickiger, Baumberger, Ferrandez, & Pailhous, 1990). On the other hand, a receding flow does not modify significantly locomotor speed. Sensitivity to optical flow and its use for motor control has already been studied in children up to 5 years old (StoffregeQ, Schmuckler, & Gibson, 1987). However, the specific effect of flow direction was difficult to document in a swinging room which does not afford prolonged unidirectional flows. In addition, walking velocity was not extensively recorded. Moreover, we may assume that visual processing in locomotor control varies during development even for children up to 12 years old. Our first results showed that young children tended to rely strongly on visual information contained in the optical flow for their locomotor control and that with age they developed a different treatment involving a progressive detachment from visual information as found in adults (Martin, Baumberger, & Fliickiger, 1992).