According to an aspect, there is provided a monitoring apparatus (2) for monitoring a user. The monitoring apparatus (2) comprises a processing unit (10) that is configured to receive first movement measurements from a first movement sensor (16) that is associated with the user, the first movement measurements representing movements of the user; and receive second movement measurements from a second movement sensor (20) that is associated with a first assistive technology, AT, device (8), the second movement measurements representing movements of the first AT device (8). The processing unit (10) is further configured to process the first movement measurements to determine if the user is walking; determine a correlation measure for the first movement measurements and the second movement measurements if it is determined that the user is walking, with the correlation measure representing the correlation between the movements of the user while the user is walking and the movements of the first AT device (8); and initiate an alert to the user to use an AT device if the determined correlation measure indicates that the movements of the user and the movements of the first AT device (8) are not correlated.La présente invention concerne, selon un aspect, un appareil de surveillance (2) pour surveiller un utilisateur. L'appareil de surveillance (2) comprend une unité de traitement (10) qui est conçue pour recevoir des premières mesures de mouvement à partir d'un premier capteur de mouvement (16) qui est associé à l'utilisateur, les premières mesures de mouvement représentant des mouvements de l'utilisateur ; et pour recevoir des secondes mesures de mouvement à partir d'un second capteur de mouvement (20) qui est associé à un premier dispositif à technologie d'assistance, AT, (8), les secondes mesures de mouvement représentant des mouvements du premier dispositif AT (8). L'unité de traitement (10) est en outre conçue pour traiter les premières mesures de mouvement afin de déte