Systems and methods for braking and releasing one or more pivot joints used in an X-ray positioning device are described. The systems and methods use a support arm that extends between a main assembly of the x-ray positioning device and an X-ray imaging assembly with an X-ray source and an X-ray detector that are disposed nearly opposite to each other. The support arm includes one or more pivot joints (such as horizontal, lateral, and/or orbital pivot joints) that allow the imaging assembly to move with respect to the main assembly. The pivot joints can each be connected to an automated braking system that is capable of selectively locking and unlocking a corresponding pivot joint, as indicated by a user-controlled switching mechanism. The braking systems containing multiple pivot joints can be individually controlled by separate switching mechanisms or simultaneously controlled by a single switching mechanism. Other embodiments are described. 19
