Chiropractic Technique Review: Pierce Results System
SOURCE: Chiro.Org’s Technique Page
The Chiropractic Technique, known as the Pierce Results System, (formerly known as Pierce/Stillwagon, or PST) was developed by Vernon Pierce, D.C., Sr. It is a biomechanical analysis of spine kinematics (or spinal motion), utilizing “stress views” of the spine (flexion, extension, rotation, and/or lateral bending views where required) or videofluoroscopy (VF, or “moving x-ray” studies) to determine the loss of spinal function, which is at the core of the “vertebral subluxation complex”.
Structure and Function
Our spine is a “structural” unit. There are 4 curves to the spine. Loss of structural integrity and/or normal function of the spine is the basis for the evolution of the vertebral subluxation. Abnormal stresses occur in the facets, discs and supporting tissues when normal motion of the spine is impaired. The Pierce System analysis is aimed at locating the specific segments which are subluxated, as well as providing the means to “free” those segments.
When normal function returns, the neurologic and other components of the subluxation complex resolve by the normal healing power referred to historically as “innate intelligence” or “vis medicatrix naturae” (the healing power of Nature).
|Neutral Lateral Film Analysis:|
The picture on the left is an example of perfect cervical lordosis. All segments should be on Georges’s line (one curved line). There should be an even spacing between each spinous process. Positioning of the head and spine should also be assessed for anterior head placement (also known as Forward Head Posture). The normal cervical lordosis (which extends from C1 to T2) should have a 17-24 cm. radius, based on the patient’s height. This is easily measured with the AcuArc ruler. The posterior arch of Atlas should be centered in the space between occiput and the C2 spinous process. If C1′s posterior arch “crowds” occiput, it is labelled as an “inferior” Atlas. If it crowds C2, it is labelled “superior”. The normal Atlas Plane line would be 18-24 degrees superior to the bottom of the film. A line under the bottom of the C2 body (Whitehorn’s line) should be parallel with the floor.
|Flexion Film Analysis:|
|NOTE: When pre-positioning the patient for this view, it’s KEY to have them first lower their chin before they flex their spine, otherwise you may not observe motion at occiput. The picture on the left demonstrates “nutation” at occiput.
Occiput reproduced with permission from Physiology of the Joints, Volume III by I. A. Kapandji, MD
The picture on the left is an example of perfect cervical flexion. When the spine flexes, it should fully reverse the cervical curve. Three primary motions should occur in flexion:
(1) The zygapophyses (facets) should slide upwards and forwards. Because of this motion,
(2) the IVF’s should open (more) fully. And lastly,
(3) the spinous processes should “fan out”, or separate.
Occiput should also nutate forwards, and the C1 posterior arch should approximate the back of occiput.
In flexion, George’s (posterior body) line should be one curved line, and all segments should be on that line. If you require more than one line to connect all the segments, the subluxated segment will reside in the portion of the spine which is straightened. In flexion lock, typically the segment just below the intersection of these 2 lines is the subluxated segment. The most obvious indicator would be that the segment fails to flex and thus, increase the size of it’s IVF.
|Extension Film Analysis:|
NOTE: When pre-positioning the patient for this view, it’s KEY to have them first raise their chin, before they extend their spine, otherwise you may not observe motion at occiput.
As with flexion, 3 things should occur. The facets should slide backwards and down, the IVF’s close down, and all the spinous processes should approximate. Unusual findings may include a segment which remains in flexion (or moves into flexion while the other segments extend). This abnormal motion is referred to as “paradoxic motion”, and is considered a sign of abnormal function of the cervical spine.
Again, all segments should remain on one curved line. Two or more lines would be needed to connect all the vertebral segments, and the subluxated vertebra will be located in the straightened section of the spine.
In this particular extension film, you may observe that C7 FAILS to extend on T1. Note the IVF size, and the fact that the spinous process fails to approximate with T1. It’s hard to visualize the facets in this view, due to the overlapping of shoulder tissue, but the inferior facet of C7 fails to slide down on the superior facet of T1. A “spot view” with increased penetration would easily display this loss of function, BUT that is NOT necessary — the IVF and spinous process clearly tell the story — this is a classic example of “paradoxic motion”.
The obvious segment to adjust would be the one BELOW the one which fails to extend. You can’t adjust the upper one from the front, to drive it back and down, but you can adjust the lower one P-A, to drive it forwards and up. Remember, the subluxation occurs at the facets on the bottom of the segment which fails to extend. So moving the segment directly below it forwards (the subadjacent segment) will break up the fixation that exists between them, and will permit the upper segment to extend, and for that IVF to close down.
You can learn much more about the Pierce analysis at our: