A humeral head assembly is provided that includes an articular body and a coupler. The articular body includes a coupling portion disposed on a side of the articular body opposite an articular surface. The coupling portion includes a continuous zone of eccentricity adjustment. The coupler portion optionally includes one or more than one discrete position site. The coupler includes a first portion and a second portion opposite the first portion. The first portion is configured to mate with the coupling portion and the second portion is configured to mate with another member of a joint prosthesis. A coupling portion with the continuous range of eccentricity adjustment can be provided on a bone anchor and the eccentricity of another component can be selected by motion of a coupler, such as a tray for reverse humeral assemblies, along the coupling portion of the anchor.
