In the current edition of the Little League’s Official Rules, Regulations, and Policies is a description and approved ruling for base runner obstruction.
Visit Rule 7.06 (b) — The Runner — to learn how a defensive player can be adjudged and penalized for committing obstruction; and how an umpire can impose penalties to nullify the obstruction.
When the obstruction occurs, the umpire shall call or signal obstruction. Obstruction is to be identified whether there is contact with the offensive player, or not. The umpire is tasked with assessing a value to the hit, and awarding bases accordingly.