A pivoting and swiveling floor treatment appliance includes a lock-prevention member that prevents a body from becoming pivotally locked in a forward/backward direction when a portion of the body is in a swiveled position. The lock-prevention member may move relative to an appliance head and to a portion of the body that swivels. In some embodiments, components of the lock-prevention member contribute to locking the swivel of the body when the body is pivotally locked.