The invention relates to a system for detecting the walk of a person, provided with a housing (BT) including an at least biaxial motion sensor (CM), said housing being suitable for being attached to the upper part of the body of said person such that a first axis of measurement of said sensor (CM) coincides with the anteroposterior axis (AP) or the vertical axis (VT) of said body, and that a second axis of measurement of said sensor (CM) coincides with the medio-lateral axis (ML) of said body, said system additionally being provided with a means (MA) for analysing the measurements output by said sensor (CM), wherein said analysis means (MA) includes: a means (MT) for processing the measurement signals output by said sensor (CM) during a window of time, including a means for searching for a dominant frequency (MRFD) in said signals and a means for detecting (MD) the walk of the person when a ratio between the dominant frequency of the signal of the first axis of measurement and the dominant frequency of said second axis of measurement, or between the dominant frequency of a Euclidean norm of the vector of measurements transmitted by said sensor (CM) and the dominant frequency of the signal of the second axis of measurement, is substantially equal to two.Système de détection de marche dune personne, muni dun boîtier (BT) comprenant un capteur de mouvement (CM) au moins biaxialτ ledit boîtier étant adapté pour être fixé sur la partie supérieure du corps de ladite personne, de manière quun premier axe de mesure dudit capteur (CM) coïncide avec laxe antéro-postérieur (AP) ou laxe vertical (VT) dudit corps et quun deuxième axe de mesure dudit capteur (CM) coïncide avec laxe médio-latéral (ML) dudit corps, ledit système étant, en outre, muni de moyens danalyse (MA) des mesures délivrées par ledit capteur (CM), dans lequel lesdits moyens danalyse (MA) comprennent : - des moyens de traitement (MT) sur une fenêtre temporelle des signaux de mesure délivrés par ledit capteur (C
