N.Y. Comp. Codes R. & Regs. tit. 9, § 4117.8
(c) A driver may use a whip only in the conventional manner. Brutal, excessive, unnecessary or indiscriminate use of the whip, is prohibited. The following actions shall be considered as excessive or indiscriminate use of the whip:
(3) whipping under the arch or shafts of the sulky.
Drivers are prohibited from kicking, punching, or jabbing a horse, or using the whip so as to interfere with or cause disturbance to any other horse or driver in a race. The use of the whip shall be confined to an area above and between the sulky shafts to include the sulky shafts and the outside wheel discs. Drivers shall keep a line in each hand from the start of the race until one-quarter of one mile before the finish of the race.