Methods and devices for manipulating an articulating arm of an ultrasound therapy system are provided. In one embodiment an articulating arm comprises a first articulating arm link, a second articulating arm link, a rotating joint configured to rotationally connect the first articulating arm link to the second articulating arm link so that the first and second articulating arm links are substantially perpendicular, and an arm limiter attached to the second articulating arm link, the arm limiter being configured to limit rotation of the second articulating arm link along the rotating joint with respect to the first articulating arm link. An ultrasound therapy transducer and imaging system can be mounted on the articulating arm. Methods for performing manipulating the arm and system are also provided.