Abstract: An elastomeric shoesole designed specifically for athletic activities wherein the sole contains at the outer side of the heel and/or the inner side of the ball transversely-extending, longitudinally-spaced openings which extend to approximately the longitudinal center line and wherein the respective opposite sides are substantially solid, thereby allowing the sole to yield at the outer side of the heel end to a greater extent than at the inner side and at the inner side of the ball to a greater extent than at the outer side.

Abstract: A standard size tennis racket has a flex of substantially 1.2 centimeters at the throat, 2.4 centimeters at the head center and 5.8 centimeters at the tip when a force of substantially thirty pounds is applied to the racket tip with the racket cantilevered from the handle end. A weight between 15 and 25 grams is located on one side on the frame at the midpoint of the strings, and a weight of between 15 and 25 grams is placed at the end of the handle, the weights being concentrated in as small an area as possible, the total weight of the racket counting the side weight only being substantially the same as a conventional unweighted racket. For a 27 inch racket, the weights are selected to establish a center of gravity between 123/4 inches and 13 inches from the end of the handle and the center of percussion between 22 and 221/2 inches from the end of the handle determined by using a pivot point 43/4 inches from the end of the handle.