Abstract: When a person wearing the wristwatch device (11) on his or her dominant arm has struck a blow, an acceleration sensor (12) senses acceleration at regular intervals of time, extracts accelerations x1 to x20 sensed at 20 points in front of the hit point H at which the sensed acceleration changes from positive to negative, and stores them in a RAM (20). The impulse force is calculated by multiplying the accelerations x1 to x20 at the 20 points in front of the hit point H by the weighting coefficients determined on the basis of the accelerations sensed in a trial performance and the actually measured impulse force and stored in a ROM (19). Therefore, the impulse force can be estimated accurately without actually striking a secured object.

Abstract: A movement measuring device determines the speed of the body's specific movement on the basis of the maximum value of the acceleration sensed by an acceleration sensing unit attached to the body, when the body has made a specific movement. For example, when the player wears the device on his arm and makes a punching motion, the punching speed is found from the maximum acceleration resulting from the punching action. Furthermore, a game device obtains data indicating the magnitude of a specific movement of the body, on the basis of the acceleration sensed by an acceleration sensing unit, and then decides the outcome of the game on the basis of the strength and weakness of the punch. This enables the user to easily play a fighting sport game involving the player's actual punching motions anywhere.