A Revised Definition of Manipulation

What a lovely surprise to see the Sandoz2 diagram differentiating between mobilization and manipulation in the commentary by Vernon and Mrozek.1 This was initially described in 1976, and, until this commentary, it has not had the coverage that it deserved.

Sandoz2 called the “dynamic barrier of resistance” the “elastic barrier of resistance” possibly because he wanted to describe the way a normal joint feels when pushed to the end of the passive range of movement: what we now call the end-feel and what Vernon and Mrozek1 call the give. I do not think the term end-feel had been coined at the time Sandoz2 wrote his article. Gillet and Liekens3 thought that an early restriction in this mode of dynamic palpation would equate to a muscular- or ligamentous-type fixation.

Joint play means a certain freedom of movement of one articular surface on the other when moved passively by the examiner.3 If a restriction was felt during this mode of dynamic palpation, Gillet and Liekens3 called it an articular fixation, meaning that the restriction was in the articulation itself and not just involving the surrounding soft tissues.3, 4 This characteristic of the articular dynamics should not be confused with the end-feel.

The point of this letter is to elaborate on how the Sandoz2 diagram can illustrate the effect of processes that directly affect the movement of the articular surfaces. Two main conditions dramatically influence the ranges of movement: arthrosis and hypermobility.

In arthrosis, the process of degeneration occurs in the articular cartilage and builds up calcium at the insertions of the joint capsule, thus limiting the amount of soft tissue involved in the movement. This is responsible for reducing the range of anatomic integrity and the ranges of active and passive movements, as commonly felt by practitioners of movement palpation. We can speculate about the order in which these reductions occur, although they probably occur simultaneously. It is fairly certain that the reduction of the 3 ranges also reduces the paraphysiological zone. This explains the near impossibility of obtaining an audible release with arthritic joints.

Conversely, in hypermobile joints, practitioners skilled in movement palpation can feel the elastic barrier of resistance becomes weaker and migrates nearer the limit of anatomic integrity, which itself is pushed a little further. This shows how hypermobile joints “crack” easily; if an adjustment is attempted within the refractory period, when the joint physiology returns to normal, it will not be possible to obtain an audible release. Any audible release then will probably indicate anatomic damage. Repeated movements into the paraphysiological zone, through mobilization exercises or adjustments, will contribute to reducing the extent of the paraphysiological zone and pushing the limit of anatomic integrity even further and cause damaging insult to the soft tissues involved.5 Thus, hypermobile joints should be rarely adjusted, if at all.