Interesting that you should ask. Just today I told my team's tank about this, he didn't know you could break the sword by charging the chainers.
I know at least two skills that do this, both are very similar, they're the charges from the sword & board and one of the Templar skill lines. I don't know if any other skills work, but I suspect that knockdowns/stuns might.
Other then shield charge, what else breaks the sword?