For levering, a bar is the tool most suited to the task. Though a makeshift tool, such as a sturdy branch or other rod-like structure may serve in a pinch, no other tool is designed for the sort of heavy-duty levering a large crowbar can perform.
Breaking
For breaking work, there are several alternatives which you may find more efficient than a bar:
A rotary hammer with breaking attachment
A heavy-duty hammer drill with breaking attachment
A pneumatic drill
Although these alternatives are more expensive than a large crowbar, they are each more effective and less labour intensive tools for the job of breaking. As they require less physical exertion than bars, they can be used for longer periods, over a wider area.