The present invention describes a system intended for measuring, evaluating or giving feedback on the sitting posture of a user, said system comprising an upper body unit 1 comprising a battery, a microcontroller, an accelerometer and a feedback-unit, said upper body unit intended for measuring an angle of the thorax at an upper body position of the user and a pelvis unit 2 comprising a battery, a microcontroller, an accelerometer and a feedback-unit, said pelvis unit intended for measuring an angle of the pelvis of the user.
