According to an example aspect of the present invention, there is provided a method for determining the direction of movement of an object, the method comprising determining a cyclical motion of a cyclically moving part of the object by recording acceleration data of said cyclically moving part over a plurality of cycles using an accelerometer or inertial sensor attached to said cyclically moving part, integrating said acceleration data over at least one cycle of movement to determine a tilting of said cyclically moving part of the object relative to the horizontal plane, measuring an external magnetic field of said cyclically moving part of the object using a magnetometer to determine an orientation of said cyclically moving part of the object relative to the external magnetic field, determining the direction of movement of the object based on the tilting and the orientation of the cyclically moving part of the object.