There is provided a method for identifying transitions between a standing posture and a sitting posture by a user, the method comprising obtaining measurements of the acceleration experienced by the user during movement; obtaining a signal indicating the height of a part of the user during movement; processing the measurements of the acceleration to identify candidate movements corresponding to transitions between a standing posture and a sitting posture; and determining an identified candidate movement as a transition from a sitting posture to a standing posture where the identified candidate movement coincides with an increase in height in the signal and an identified candidate movement as a transition from a standing posture to a sitting posture where the identified candidate movement coincides with a decrease in height in the signal.