- Developmental or embryologic
- Structural or morphological
- Functional or physiologic
- According to the instantaneous axis of motion
Regardless of which is chosen, there are two questions that should be considered by the clinician:
- Joint range of motion (ROM) is dependent upon what?
- The limit of range of motion is determined or limited by what?
- The extent of the articular surfaces
- The shape of the articular surfaces and their asymmetries
- The laxity of the ligaments and capsules
- The condition of the muscles, tendons, disc, and other holding elements
B. The limit of ROM is determined by:
- The "locking" of the articular facets and their orientation with respect to each other
- The approximation of associated soft tissues
- The tautness of ligaments
- The passive tension created by fully stretched muscles and fascia, i.e., the function of the thoracolumbar fascia and lateral raphe during anterior saggital rotation
The importance of all of the above is in its clinical application and practicality in decision making. In summary:
- The size and shape of articular surfaces determine the type and degree of articular joint motion.
- Therefore, joints have predetermined and specific physiological ranges of motion with the result that forces acting upon joints produce change in the contiguous relationship of opposing articular surfaces that make up the joint.
- Forces of too great a magnitude or of incorrect direction may cause articular disharmony, and forces of insignificance do nothing. Mastering the art of motion palpation solves this situation.
Considering these facts, it follows that during your motion palpation exam and subsequent treatment, the following general concepts should be applied:
- Analysis of the relationship of all the component parts of a specific joint, together with knowledge of its physiological range of motion, is essential for the correct examination and diagnosis of the articular dysfunction.
- Adjustive procedures (osseous adjustments) delivered for the purpose of restoring normal ranges of motion must be given in accordance with the motion restriction physiologic for that joint.
- The contiguous articular surfaces of a joint in "fixation" must retrace the path through which they traveled in order for the normal relationship of joint surfaces to be re-established.
- Specific joint adjustments (as taught in all MPI courses) decrease the chance of strain of closely related articulations and is non-traumatic, provided the condition of the surrounding holding elements and tissues for the control of the joint function is determined prior to treatment.
Disturbances of articular motion may be due to a defect of osseous structures, muscular disharmony, articular malfunction of intra- or extracapsular origin and/or faulty locomotor patterns.
There is a function of an articulation that is seldom fully appreciated or recalled: It stimulates the proprioceptive receptors, giving knowledge of position of parts in space, and by its influence on related parts, it has much to do with balance, position, and compensatory changes often recognized as hypermobile segments. The articulation then relates to the neural mechanisms at a given level, thus aiding in maintaining equilibrium.
The previous paragraphs point to the intricacies associated with the subluxation complex. The frequency with which the "subluxation complex" is increasingly found in literature is testimony to its diagnostic value in chiropractic. It is not my intention to discuss the pros and cons of such value, but rather to point out that it does exist in rationale literature.
Keith Innes, D.C.
Dr. Innes will be conducting his next Somatic Components of the Subluxation Complex seminar on May 16-17, 1992 in Detroit Michigan. You may register by dialing 1(800) 327-2289.