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CAPA si_sept_1991

Segmental Standard Rotation

Pages: 2-6
Year: 1991
Notes on S.I

Notes on Structural Integration – September 1991 – 91/1

Volume: 91/1

In the field of Structural Integration, the term “rotation” is used in two ways. In the broader sense it corresponds to the general definition of a body “turning around an axis” (Webster’s). The axis may have any location and direction, but most important are the three axes of the coordinates of the body derived from the vertical of the gravity field and the configuration of the body in neutral stance. In the narrower sense, “rotation” means a turning around the vertical or the long axis of the body. Rotation around the two axes which are horizontal in standing are called “tilt” and “side-tilt”.

Functionally, rotation describes a movement around the long axis. Structurally, “being rotated”, it identifies the state along this path of movement with reference to the normal structure in neutral stance (the state of “no rotation”) as if part of the body, however defined, had moved from “normal” to its currently observed position.

Rotation proper, around the vertical, is fundamentally different from that around the two horizontal axes. The vertical is immutable, its direction absolute, being given by the gravity field. Only its location depends on where the body is, and of that only the gravity center is needed. For the transverse and sagittal axis, the gravity field only determines that they must lie in a horizontal plane. In order to find their exact orientation the configuration of the body must be considered. Since there is nothing absolute about that and no invariable indicator exists, defining the orientation of the horizontal axes is always arbitrary to some degree. Usually the client is simply asked to stand facing the Rolfer. The problem is resolved well enough by relying on the client’s understanding of “facing straight”. Sometimes it is obvious however that the client’s eyes may face the Rolfer straight on, but that his body as a whole or in part is turned away a little.

The difference between rotation around the vertical and that around the horizontal axes becomes evident when rotation is analyzed. For diagnosing tilt and sidetilt the gravity field is used. Equilibrium in a normal structure is generally of the labile or unstable type. Slight functional rotation, movement around the horizontal axis, will reliably reveal the direction of rotational deviation. It is passive away from the equilibrium but requires muscle force toward it. Gravity does not help with rotation proper. All parts of a given unit move in a horizontal plane in this case and balance is not disturbed.

The block model is used here to describe structural rotation. It illustrates directly that rotation of segments around the vertical does not affect balance, whereas tilt and side-tilt, as well as shift, do. To find the structural rotation of a segment, its orientation to the left or right with respect to the segment above and below must be determined. The point is important because in practice, rotations are usually analyzed in a different way. The client is asked to stand facing the Rolfer, which defines the frontal and sagittal planes in his body. The orientation of a segment is then compared with this overall framework. This can be misleading at times as the segment under observation may be rotated e.g. slightly to the left with respect to the body coordinates. But if there is an even greater rotation to the left in the segment above or below, the observed segment is actually rotated to the right with respect to it.

Gravity does not offer a clue, but the “boxes in the shopping bag” model provides the method for deciding on the structural rotation of segments. In a normal structure standing without rotation, there is no strain in the bag. This statement can be made a little more realistic by replacing it with: whatever strain there may be in the bag is balanced all around. If a segment is rotated by an outside intervention, or by “muscles”, a rotational strain is induced in the shopping bag. When the force is released again, the imbalance in strain, or “passive tissue tension”, will take the segment back again exactly to normal, where there is “no rotation”.

Real structures however have structural rotations. When they stand easy, at their “rotational structural point”, the rotations show but passive tissue tension is balanced as far as rotation is concerned. This constitutes a kind of stable equilibrium because any functional rotation, toward or farther away from normal, requires force. When it is released, tensional imbalance in the bag induced by the movement will take the body back to the structural point.

Theoretically, the method for determining the structural rotations of all segments is simple. The body is brought into neutral stance, where shifts, rotation, and tilts are absent. This is assumed to remain so for tilt, sidetilt, and shift. When musculature is relaxed, the imbalance in passive tissue tension induced originally which is rotationally active will cause all segments to rotate in the direction of their aberration. The method is not very practical, however. First, the inherent arbitrariness in determining “no rotation” for a segment renders it impossible to place it there exactly. Secondly, trying to align all segments perfectly at the same time would be a futile task; they would always escape sideways because they are interdependent, being contained in one and the same large “bag”. But a modification of this hypothetical procedure serves well to decide on the rotation of the pelvic segment from which that of the others can be determined.

The terminology used here follows anatomical and physical conventions. The segment in question is observed from the point of view of the client, looking down on it from above. Then the rotation appears as clockwise or counter-clockwise. Traditionally, clockwise and counter-clockwise rotations are termed negative and positive, respectively. So when the left hip is forward and the right one back, rotation is clockwise or negative. With the right hip forward and the left one back, it is counterclockwise or positive.

In the course of examining segmental rotations it turned out that there seems to exist a pattern through the body which is the same for everyone examined. That does not mean that it can’t be disturbed or that a segment may not be rotated in the other direction. But there apparently does not exist a symmetrically opposed pattern where all the segments are rotated in the other direction.

<img src=’https://novo.pedroprado.com.br/imgs/1991/1039-1.jpg’>

Fig.1- Normal arrangement of a stack of blocks, representing neutral stance (left). Tension in the elastic sack is balanced, indicating “normal structure”. When one block is rotated (right) the tensional imbalance created will restore the original arrangement by itself.

<img src=’https://novo.pedroprado.com.br/imgs/1991/1039-2.jpg’>
Fig.2 – In the “aberrated” arrangement (left) tension in the elastic sack is balanced, representing an “aberrated” structure at its Structural Point. When it is brought to neutral stance, a tensional imbalance is created which will take the blocks back to its “aberrated” position.

Pelvis (-)

The client is asked to extend against the ground. As usual, instructions must be given because most clients simply raise their chest, bringing the body away from neutral stance instead of more towards it. Extension improves all structural parameters functionally. The lengthening along the central axis unwinds the rotations.

Standing behind the client I place my hands on the hips. I ask the client to keep the legs and the upper body still in space, allowing only the pelvis to be soft so I can rotate it. I do this lightly so that it virtually oscillates forth and back around a vertical axis by itself, trying to find a rhythm. Care must be taken that the pelvis does not swing around but only rotates around its gravity center. Because structural rotation is diminished in this stance which is closer to normal than the structural point, turning toward normal and across it in the opposite direction immediately meets strong resistance. Movement in the direction of the aberration is in stark contrast: it is initially passive, effected by the imbalance in passive tissue tension. One finds that rotation into the aberration requires no effort, or at least distinctly less, and that the movement is smoother and goes farther than in the other direction.

General consideration must be given to the possible internal movement in the pelvic segment. The right sacroiliac joint seems to be freer than the left one generally – probably because of standard torsion of the pelvis. If movement is allowed there, the result is opposite and false. Extension of the knees and even some hyperextension “locks” the sacroiliac joints and guarantees that the structural rotation of the pelvic segment as a whole is diagnosed and not intrasegmental mobility.

Almost always the rotation found is negative.

<img src=’https://novo.pedroprado.com.br/imgs/1991/1039-3.jpg’>
Fig.3 Schematic drawing of segmental standard rotation.

Thighs (+)

The two thighs together form the thigh segment. Its rotation can be found by adding together the rotations of its two “half-segments”. One almost always finds that the resulting sum rotation is positive. With internal rotation of the femora, the right one is rotated internally more than the left. With external rotation, the left one is rotated externally more than the right. When the impression is that of a “mixed rotation”, the right femur is internal, the left external.

If the thigh segment were exactly in line with the pelvis, which is rotated negatively, the findings would be exactly the opposite. The thighs would also face to the right. Sometimes one sees “no rotation” or even a slightly negative one when looking at the thighs. Usually this impression is corrected easily when one realizes and observes that the reference line, the frontal plane of the pelvic segment, is not in the frontal plane of the whole body but rotated negatively, facing to the right. So even if the thighs appear to face straight forward or slightly to the right from the observer’s point of view, one will usually find that they are rotated positively, to the left, with respect to the pelvic segment.

Lower Legs (-)

In the segment of the lower legs, the two “half-segments” are also examined separately and the results combined. The left lower leg is almost always pretty much in line with the left thigh, more so than the right one. The right lower leg is regularly rotated externally with respect to the right thigh so that for the whole segment a negative rotation results.

Rotation is assessed by comparing the hinge axes of knee and ankle. In externals, the left knee hinge is generally rotated externally more than the right one because of the positive thigh rotation. If both lower legs were in line, the left ankle hinge should also be more externally rotated. But one usually finds that the right ankle hinge is more external; the medial malleolus is more anterior on the right side, the lateral malleolus more posterior, than on the left side. With internals the ankle hinges are often not rotated internally. The lower legs seem to compensate for the internal rotation of the thighs by turning out a little. Again one finds the left ankle hinge rotated externally less than the right one.

Comparison of knee and ankle hinges on both sides shows that the discrepancy is on the right side. The angle between the knee and the ankle hinge, referenced against the frontal plane of the body, is greater on the right side. The external rotation of the right lower leg is shown clearly by the medial plane of the tibia. It faces forward toward the observer more on the right side, at least when one looks at the knees from an angle which shows the knee hinges transverse or at an equal angle with regard to the sagittal plane of the body.

A specific difference in the intrasegmental configuration of right and left lower leg is regularly observed. In the right lower leg the lateral malleolus is farther back than on the left. It has little choice but to go with the medial one, which is forward, and the distal end of the tibia, which is much more massive than the fibula. But above, the head of the fibula is not back correspondingly but regularly comes around and forward. With the external rotation of the right tibia, which forms a strong indicator for the rotation of the segment, the distance between the tuberositas tibiae and the caput fibulae is usually distinctly less than on the left side. This constitutes an intrasegmental torsion. It makes the right lower leg more rigid, acting perhaps to help to stabilize it against shear and stress coming from the “conflicted” right knee.

Feet (+)

Positive rotation is not a certainty here. The feet go in various directions in different ways. But a tendency can perhaps be detected for the right foot to turn medial. It is not clear whether this deviation in the positive direction is intersegmental, between lower leg and foot, or intrasegmental, within the foot segment. It would serve well to compensate for the stronger external rotation of the right ankle hinge. The left foot seems to be more in line just as the left lower leg.

Thorax (+)

The positive rotation of the thoracic segment can be seen most frequently in two places. From the front, the first two ribs fall back more on the left side. From the back, the 10th rib is more forward on the right side. But the rotation is most obvious at the shoulder girdle. It almost always seems to go with the rotation of the underlying thorax so that the left shoulder is farther back than the right one.

The situation is complicated for at least two reasons. First, the thoracic segment is large and not sufficiently defined. The status of the shoulder girdle is not clear either. As it seems to go with the thorax surprisingly often, its proximal parts can be counted as part of the thoracic segment. The upper arms must definitely be regarded separately, however. They often differ from the configuration of the central “yoke”.

Another kind of complication arises from the apparent impression that with the thorax there also seems to exist an intrasegmental twisting, similar to that of the pelvis. Generally the right half of the thorax appears as shorter along the long axis, being broader, and flatter than the left one. Moreover, modifications resulting from the different side-tilt of the pelvis related to differences in leg length seem to overlie this.

Head (-)

The head is rotated negatively. The reference here is the upper thoracic aperture, or better still, the shape of the sagittally biconvex plane between the clavicles in front and the free margin of the trapezius in back, which to some degree represents the posterior part of the first rib.

Discussion

It is amazing that such a simple pattern of a standard rotation through the body should exist which is not known to anatomy, as far as I am aware. Furthermore, exceptions and disturbances are not even very frequent, and a symmetrically opposed pattern, which apparently cannot be found, must at the least be very rare. It is also astonishing how constant the pattern is and how reliably it turns up in analysis once one has “seen” and understood it.

The reasons for the pattern are unknown. It is not related to handedness, nor to left/right issues or front-to-back types. Perhaps the explanation lies with another type of rotation. The intestines rotate positively, seen from behind, by 270° in the early life of the embryo. This should influence the configuration of the back to which they are fastened by the mesenterium and from which they are suspended. There is also a sort of rotation in the thorax which brings the heart to lie more on the left side. This should make itself felt in the anterior and posterior wall of the thoracic cavity because the heart is embedded in the mediastinum. This forms something like a large septum in the sagittal plane of the body spanning the thorax along its whole length.

It may have been noticed that two segments are absent in the description: the neck and the lumbar segment. They have relatively little definition in themselves. As spacers they only possess vertebrae, and these lie excentricly and probably only shape the posterior wall of the segments clearly. Segmental shape then appears to be largely determined by the rotation of the segments above and below. The neck and lumbar segments are something like “transitional segments” as far as rotation is concerned. They show a torsion in a specific sense. The proximal end, as a ring, of the lumbar segment is rotated positively by the thorax. The lower end is rotated negatively with the pelvic segment. The latter often appears as accentuated because of intrapelvic torsion.

The neck usually shows a similar torsion. Its lower end is largely shaped by the fasciae attaching to the positively rotated thorax and shoulder girdle. Cranially its shape is determined by the negatively rotated skull. Because the shoulder girdle generally goes with the thorax, the sternal end of the right clavicle is usually more medial and also anterior than the left one. The sternal attachment of the right sternocleidomastoideus is also often more forward and medial. At the mastoid, it is more posterior than on the left side because of the negative rotation of the head. This may contribute to the general occurrence of a right convex bend in the neck with the caudal cervical vertebrae and the soft tissue being more forward and appearing also narrower on the right side.

Intrasegmental pelvic torsion is in the same direction as pelvic segmental rotation concerning the orientation of the lateral aspect of the pelvis, the hips, and augments the effect. The acetabulum is turned back more on the right side by both criteria. The right thigh should be rotated more externally than the left because of it. But exactly the opposite is the case as is shown by the positive rotation of the thigh segment. In the bony view, it appears that at the hip joints there is a fairly constant “conflict”, which is symmetrically opposite between left and right. The right ilium tends more toward “external”, the right femur toward “internal”. The left ilium is more “internal”, the left femur more “external”.

The legs also seem to be differentiated in a more basic respect. The left leg, below the ilium, appears to be more in line from thigh to foot. The joints from hip to ankle also generally seem to have less freedom than on the right. The right leg is generally the more “conflicted” one. Ilium and lower leg shift it strongly to the external side, while thigh and foot seem to counteract this tendency. Apparent, typical, and relatively constant “conflict” in hip, knee, and ankle is the result, while on the left side knee and ankle are more “congruent”. The joints on the right side also seem to have more freedom. One has often the impression that thigh and foot “would like” to rotate externally to be more in line with the segments above, especially when there is no weight on the leg. This leads one to suspect that the negative rotation of the pelvis, with the “external” tendency of the right ilium, and of the lower leg is in some way “primary” while thigh and foot react by going the other way, to maintain overall structural integrity. The further thought arises that segmental rotation, as is evident phenomenologically, could be a relatively superficial aspect of “deeper” rotations, of which pelvic torsion, right lower leg torsion, and the so far not described intrasegmental shape of the thorax could be manifestations.

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