Abstract: Apparatus for diagnosing the; locus of a swing, such as a golf swing, from back-swing through ball impact to follow-through by an arm pivotally mounted near the inner end in a base member attachable to a person's body and attachable at the outer end to a club shaft, the inner end being slidingly connected to crossed members rotatably mounted at their ends in the base member to operate rotatable variable resistors which produce voltage change signals which are transmitted to a computer with readout or recording device so that the loci of the swing can be observed.

Abstract: A swing diagnosing device utilizes a recording plate having an indicating surface fitted to the front surface of a supporting plate attached to a base plate, and a rotary ball is borne by a cover fixed to the base plate. A shaft pipe projecting out of an arm is passed through this rotary ball, a supporting metal piece fixing the grip end of a golf club is attached to the lower end part of the arm, and a recording means is fitted to the tip of the shaft pipe at the upper end so that as the arm is operatively rotated with the golf swing the locus of the swing is recorded.