Au contraire on the pitching rules. These have been around for some time now. From the 2011 preseason manual (which is available online at ohssa.org):
Rule 6-1-6 (page 39)
Each state association shall adopt a pitching restriction to afford pitchers a reasonable rest period between pitching appearances.
No player may pitch in more than l0 innings in a three day period. This regulation is mandatory. The following examples are all permitted:
S M T W T F S
0 0 7 0 0 7 0
0 4 3 2 5 3 2
3 3 3 3 3 3 0
0 10 0 0 7 0 3
0 0 7 0 0 7 3
0 0 0 0 0 6 4
0 0 6 l 0 9 l
The limit is on a player as a pitcher. If he can pitch with either arm he is limited as a pitcher, not ten innings per arm. A player pitching in an eleventh inning in a three-day period is considered an ineligible player.
Any part of an inning is considered as an inning relative to the pitching rule.