Abstract: The described apparatus is adapted to strap to the arm of a bowler or golfer to restrict the "breaking" of the player's elbow on making the bowling delivery or in completing the golf stroke so as to enable repetitive deliveries and/or strokes to be duplicative of one another for improved consistency of performance. The apparatus includes a pair of straps which encircle the user's arm above and below the elbow. The arm encircling straps are joined to each other by two pivotally connected sections, and the force required to move one section relative the other may be varied by a setscrew which passes through one section and bears against a land on the other section. Spaced apart pivot apertures in the pivotally connected sections enable such sections to be disassembled and then reassembled to each other at different pivot positions, to provide a size adjustment.