A power injector that incorporates at least one signal transmission connector in a movable joint (e.g., between a powerhead and a support or stand between at least one adjacent pair of support sections of a support for the powerhead) is disclosed. Such a signal transmission connector may be in the form of a slip ring module, but in any case is part of the signal transmission link to the powerhead. At least that portion of a signal transmission conduit that is adjacent to the powerhead may be disposed within the interior of the corresponding portion of the support or stand, thereby reducing the potential that an individual will grab onto the signal transmission conduit when attempting to move at least part of the power injector, to change the position of the powerhead, or both.