0379投球者:名無しさん
2018/09/19(水) 17:18:42.80ID:M6XvYlPU2.3.3 A delivery must be made entirely by manual means.
2.3.5 A player may use special equipment to aid in grasping and delivering the ball if it is in place of a hand or major portion thereof lost by amputation or otherwise.
https://www.worldbowling.org/wp-content/uploads/2014/06/World-Bowling-Statutes-and-Playing-Rules-2016-01-01.pdf