According to an aspect, there is provided a computer-implemented method for analysing movement of a subject. The method comprises obtaining, from a movement sensor in a device that is carried or worn by the subject, a movement signal representing movement of the subject during at least a first time period； obtaining, from an air pressure sensor in the device, an air pressure signal representing air pressure at the air pressure sensor during at least the first time period； processing the movement signal to identify a plurality of occurrences of a gait phase corresponding to the subject walking； for each of the identified occurrences of the gait phase, selecting a respective part of the air pressure signal corresponding in time to said occurrence of the gait phase； for a plurality of pairs of identified occurrences of the gait phase, determining a change in altitude of the subject between the identified occurrences of the gait phase in each pair from the respective selected parts of the air pressure signal； and determining if the subject has traversed stairs from the determined changes in altitude for the pairs of identified occurrences of the gait phase. A corresponding apparatus and computer program product are also provided.
