To break a lance for somebody means that you are standing up for that person. It may, however, also point to sexual tension, as well as religious themes (the Grail). Jung saw a connection to the fisher king, who was injured in the groin by a lance, and therefore relates the symbol to physical and emotional suffering. He claimed the task of the hero (Percival) is to address the question of empathy / sympathy in the face of this suffering.
If empathy is not expressed, the king and his court will continue to suffer.
According to Freud, as with all other weapons this is a phallic symbol.
[1]Symbol: The lance—one of the oldest weapons of man—is also a phallic symbol.
Vision: Seeing a lance means a fight—instigated by others—is about to break out.
If you are handling a lance: because of your actions, you will be the one to start a fight.
Depth Psychology: As a phallic symbol, the lance also refers to sexual appetites.
See Also: Weapon.
[2]