Abstract: A device that characterizes the trajectory followed by a movable object after a piece of sporting equipment comes into contact with the movable object, e.g., by identifying velocity, the distance that the object would travel if unobstructed in standard ideal conditions, the curvature of the path travelled by the object, the direction of travel of the object, or the direction or magnitude of spin of the object. The device includes at least one force sensor element arranged to be located on the piece of sporting equipment, which is held or worn by a user. The sensor element detects at least a component of the force of contact between the piece of sporting equipment and the movable object. The sensor element provides a signal representing the intensity of the component of the force of contact when the contact occurs. An electrical processing circuit is arranged to receive the signal from the sensor element and to process the signal to produce an output characterizing the trajectory of the movable object.