Abstract: A main frame is provided including front and rear end portions and the front end portion includes a pair of laterally spaced apart hitch structures for releasable hitching to a pair of complementary hitch portions carried by the rear of an associated towing vehicle. The rear end portion of the frame includes a pair of laterally spaced apart dependingly supported caster wheel assemblies which are each mounted from the frame for full 360.degree. angular displacement relative to the frame about an upstanding axis. Connecting structure interconnects the caster wheel assemblies together for equal and simultaneous angular displacement relative to the frame and friction brake structure is operatively connected between the frame and at least one of the caster wheel assemblies frictionally resisting angular displacement thereof relative to the frame.

Abstract: A method and apparatus designed and constructed to be used as an accessory on X-ray machines when making X-ray pictures on X-ray film of the lower extremities of the human body for the specific purpose of accurately measuring the long bones and the joint spacing. Also the analyzationand comparing of the long bones and joint spacings with each other.The radiographic attachment apparatus is a separate unit from the X-ray machine and is not attached as a part thereof, but used as an accessory by merely placing the apparatus in the center of the X-ray table under the lower extremities of the body when making the X-ray pictures.