Hello,
for rule 12.9, you have added the notion of “Extended” arms or legs.
As a follow through, it means that if my arms or legs are NOT extended, then there is no violation. And we add the complication of what is Extended, fully extended, partially extended…
Maybe to be clearer it could be :
Players may not use their arms or legs (extended or not) to obstruct the movement of opposing players
In my personal experience, it often happens that a defensive player may use their knee to block a path of the close cut of the offense. As of current rule 12.9 that was a violation, but with this new modification the leg is not “extended”, so would it be 12.7.2 rule.