that's correct, in spinal conditions , because the ubiquitous nature of a protective muscular splint , hypermobility would only be possible were this not to occur. I have yet to come across a living human being where complaints of either referred events from the spine , or pain and dysfunction immediate to the spine was occurring , where protective responses where not easily observed. As for the so called "bony block", in similar circumstances this interpretation of a powerful contracture may be made . I am yet to observe such a state which could objectively be described as bony block . I work mostly in an outpatient setting where infections of joints are extremely rare indeed ( none in twenty years plus ) worthy of genuine caution should the therapist have reason to suspect same however.