Abstract: A bowling shoe to be worn on the sliding foot of a bowler has a heel that presents outer and inner bottom surfaces, the outer bottom surface having a relatively high coefficient of friction as compared to the inner surface. The outer surface can be white rubber and the inner surface can be leather. Preferably the heel is U-shaped for improved stability. A shoe for the non-sliding foot has a sole with a higher coefficient of friction and a uniform heel surface.

Abstract: A unique hand grip is provided for a bowling ball wherein the lifting fingers work in unison to provide a single balanced lifting force directed toward the thumb. This is accomplished by use of an appropriately sized elliptical finger cavity which receives a bowler's middle and ring fingers therein. An alternative embodiment encompassing two thumb holes provides two separate grips utilizing the same elliptical cavity to obtain distinct and separate performance characteristics in a single bowling ball. Finally a method is provided for rehabilitating a conventional bowling ball and improving it by the removal of the traditional finger holes therefrom and the addition of an elliptical cavity as a replacement therefor.

Abstract: A strap, preferably elastic, extends between the middle of a bowler's back and the upper portion of the bowler's free arm. It inhibits rearward movement of the bowling shoulder and/or rotational movement of the shoulders that could result in a follow-through angle of less than ninety degrees. The strap, which preferably is at least partially elastic, can extend between a body belt that encircles the bowler's torso at the waist and an arm belt that encircles the free arm in the biceps region.

Abstract: An apparatus for measuring the imbalance of a bowling ball includes a base, a first gimbal rotatably mounted on the base and a second gimbal rotatably mounted on the first. A ball is supported by the second gimbal and spun while having the same orientation it has when in flight. The ball acts as the rotor of a gyroscope and any imbalance causes precession in the form of rotation of the first gimbal. Indicators carried by the first gimbal and the base aid in observing the direction and rate of precession.