US Patent 8657707 Swing analysis method

An analysis method includes the steps of: measuring a swing of a golf club to which a sensor capable of measuring accelerations in directions of three axes and angular velocities or angles about the three axes is attached; obtaining an index for classifying the swing based on a measuring result of the sensor; and classifying the swing based on the index. The index includes the item (a) or (b): (a) a grip angular velocity at least at one time during a downswing; and (b) a grip velocity at least at one time during the downswing. Preferably, times of an address, a top, and an impact are determined in the analysis method.