Downstick

A downstick is a weapon held with a reverse grip in the off hand, especially behind a shield. It is mostly used defensively to protect the legs and lower torso, but is a possible threat as it can be used offensively to swing or stab. Often the downstick is a sword because it can be held flat against a shield, but bats are also common downsticks. Some fighters prefer spears, especially javelins, as downsticks. Occasionally a club or mace will be used as a downstick, which makes sense given how much striking surface of a sword or bat is unusable while hidden behind a shield.