According to a first aspect the present invention provides a method of monitoring posture of a user, the method comprising: - obtaining first pressure sensor information from a plurality of sensors upon a first item of furniture occupied by the user at a first time; - obtaining first sensor position information defining the relative positions of the sensors upon the first item of furniture; - processing the first pressure sensor information and the first sensor position information to determine a first user posture upon the first item of furniture; - obtaining second pressure sensor information from a plurality of sensors upon a second item of furniture occupied by the user at a second time; - obtaining second sensor position information defining the relative positions of the sensors upon the second item of furniture; - processing the second pressure sensor information and the second sensor position information to determine a second user posture upon the second item of furniture; and - determining a cumulative load upon the user’s spine from the first user posture and the second user posture.