Lordosis is the name for a sagittal plane curve in any area of the spine, concave to the posterior. (Kyphosis is the name for a similar sagittal plane concave to the anterior.) The normal spine presents a double S curve. Viewed from the back, the normal neck is concave, the thorax convex, the lumbars again concave, and the sacrum and coccyx convex. An appropriate amount of curve gives the spine springiness. Either too much or too little curve results in poor shock absorption with each footfall. The lumbar portion of the spine can have excessive curve, normal curve, insufficient curve, no curve or curve in the wrong direction. (See Figure 1 below.)
Figure 1. Lumbar curve can be excessive, normal, insufficient, or in the wrong direction.
The degree of lumbar curve is most accurately expressed by the relationship between the bodies of the vertebrae, and is most accurately visualized on an X-ray. It is rarely advisable, though, to undergo radiation exposure for the sole purpose of assessing the degree of lordosis. The spinous processes of the lumbar vertebrae are our best access for palpating lumbar curve. However, the curve expressed by the tips of the spinous processes is not identical to that of the bodies of the vertebrae in one and often two ways. Figure 2 demonstrates how the degree of curve expressed by the tips of the spinous processes is less than the curve expressed by the anterior surfaces of the lumbar vertebrae.
Figure 2. Variations in the length of lumbar spinous processes can give false impressions of lordosis.
Within a given person's spine, individual spinous processes also vary in length. Figure 2, above, shows variations in spinous process length that make the curve expressed by the tips of the spinous process differ between individuals from the curve expressed by the bodies of the vertebrae. While the tips of the spinous processes are our best palpatory indicator of lumbar curve, keep in mind that they usually express less than the actual curve, and the amount of difference from the actual curve varies from person to person, depending on the relative lengths of each person's spinous processes.
This brings us to functional considerations. Assessing lordosis, or any feature of alignment, is at most half the story. The greater questions are: "How well does it move?" and "How comfortable is it?"
Returning to alignment, the next problem is the relationship of the lumbar curve to neighboring structures. Above the lumbar spine is the thorax, and below the lumbar spine are the sacrum and pelvis. Let's begin with the pelvis.
The orientation of the pelvis can vary in any plane. Lordosis varies in the sagittal or anterior-posterior plane. We will also consider sagittal plane variation in pelvic orientation. Rotation around the hip joints in the sagittal plane yields anterior and posterior tilt of the pelvis. We name the top of the pelvis sitting forward, or anterior of the bottom of the pelvis, as "anterior tilt." Similarly, the top of the pelvis sitting back of, or posterior to the bottom of the pelvis, is "posterior tilt."
Figure 3. Pelvic tilt and sacral angle are independent.
Occasionally, a client will come in and say that he or she has an anterior tilt, but what is really meant is that the bottom of the pelvis is forward of the top. It is essential to explore what each client means by his or her terminology.
In the minds of therapists, anterior pelvic tilt is often associated with excessive lumbar lordosis. The logic of this is straightforward: If the pelvis is tilted forward, the lumbars start out forward and must gradually curve back in order for the thorax to be above the pelvis instead of forward of the pelvis. Logical as this may seem, this correlation is not very strong. The reason is that there is also variability in the orientation of the sacrum between the iliac portions of the two halves of the pelvis.
Figure 3, above, shows five of the many possible relationships between the sacrum and the pelvis. Four of the five lumbar curves shown are inconsistent with the pelvic tilt from a purely pelvic tilt/lumbar curve model.
Figure 4. Soft tissue rarely tells the real story about body alignment.
As an exercise, assemble six or more colleagues. Assess pelvic tilt by a method described below, and assign each person a sequential number, with No. 1 having the most anteriorly tilted pelvis, and the highest number the most posteriorly tilted pelvis. Then reassess this same group for degree of lumbar curve by the method described below, assigning No. 1 to the greatest lumbar curve, and the highest number to the least lumbar curve, or hopefully not the greatest lumbar kyphosis in the group. In most groups there will be poor correlation between the two sets of numbers. The two features (lumbar curve and pelvic tilt) must be assessed and recorded separately.
Assessing Pelvic Tilt
A number of methods are used to assess pelvic tilt. The first distinction to make is that we want to assess the degree of tilt of the bony pelvis. As you will see, soft tissue adds complexity to this assessment. Soft tissue is important to assess, but for pelvis orientation, it is imperative to assess the bony structure.
Surrounding the pelvis are two primary types of soft tissue: muscle and adipose. The amount and distribution of each type of tissue varies widely from person to person. Figure 4, above, shows how soft-tissue structures affected by genetics, exercise and diet usually give inaccurate perceptions of bony-pelvis orientation.
Bony-pelvis orientation cannot be reliably assessed from an observation of skin contour, even in the thinnest of people. Bony palpation is essential. The pelvis has several bony landmarks that have potential value for assessing orientation.
In Figure 5 below, line A between the superior surface of the pubic symphysis and the tip of the coccyx is not useful for assessment since the coccyx is variable in both length and orientation. Line C between the anterior superior illiac spine (ASIS) and the posterior superior illiac spine (PSIS) is frequently used for assessing pelvic orientation. There are, however, three problems with this line. First, because the PSIS is a broad prominence, judging its highest point is subjective. Second, the acute angle at the inferior margin of the PSIS is a clearer landmark than the prominence itself; however, this angle will sit a variable distance inferior to the horizontal line through the ASIS. Third, the PSIS is often under considerable soft tissue, making finding its exact apex even more challenging.
Line B, between the ASIS and the anterior superior margin of the pubic symphysis, is easier to locate. Both of these landmarks are sharper points than the PSIS. Even in fairly obese persons, both of these prominences can be reliably palpated. All three points, the two PSIS' and the anterior superior margin of the pubic symphysis, should lie in a coronal or frontal plane. Assuming the person is standing, this plane should be perpendicular to the floor. Angular deviation from a vertical plane represents forward or backward tilt. For this phase of analysis, ignore one ASIS being forward of the other; that is a separate issue.
The next problem is variability in pelvic proportions, which vary as much as facial proportions. Lines A and C in Figure 5 are rarely parallel to each other or perpendicular to line B, as they are in this idealized diagram. One of several features is gender variation. In adult females, the ASIS' tend to be farther forward than in males. However, within each gender there is considerable variability. Some women have features of their pelvises that are more "male like" than most males, and visa versa (see Figure 6). The best plan is to assess both lines B and C, and also to consider functionality. Does the pelvis move appropriately in its several joints, and how comfortable is the person? If it does not move well and/or is not comfortable, does the apparent tilt of the pelvis make sense in terms of the symptoms?
Figure 5. Landmarks for assessing pelvic tilt are shown above.
The next problem deals with sacral angle. The sacroiliac joints have several directions of mobility. In addition to normal physiologic motion in walking, breathing and craniosacral rhythm, various placements and displacements of the sacroiliac joints give a wide range of sacroiliac relationships. One dimension of sacroiliac positional variability is anterior/posterior tilt with respect to the ilia (see Figure 7 below).
Assessing sacral angle by palpation is challenging, since at least the base of the sacrum may be under two or more inches of soft tissue. Unlike the lumbar vertebrae, the sacrum lacks prominent spinous processes to help us assess orientation. The point for our current consideration is that the sacrum is not part of the lumbars and may vary in any direction from the orientation of the lumbars. When assessing lumbar curve, assess only the lumbars, not the sacrum.
Figure 6. Pelvic proportions vary as much as fascial proportions.
Having considered the area below the lumbars, we will now consider the area above the lumbars--the thorax. The pelvis has a left and right innominate bone, a sacrum and a coccyx. Externally, these few bones articulate with three other bones, the femurs and the fifth lumbar. The thorax is more complicated both internally and externally, containing 12 vertebrae, 24 ribs, a sternum and a manubrium. It articulates with the 1st lumbar vertebra, 7th cervical vertebra, two clavicles and two scapulae. The shoulder girdle is mobile over the rib cage, and can give false visual impressions of the orientation of the thorax. In all, the thorax has about 150 articulations.
Within this complexity, one feature of the thorax is that as a whole, it can lean forward or backward in a sagittal plane.
Figure 7. Pelvis and sacrum can relate in many different orientations.
In all three of the drawings in Figure 8, above, the pelvis has near-normal orientation, and the lumbar curve does not vary. Notice that in the figure on the right, skin contour gives an impression of greater lordosis. In assessing lumbar curve, the orientation of the thorax is not to be considered. The orientation of the sacrum and the orientation of the thorax are of considerable interest, but neither of these orientations are to be considered in assessing the degree of lumbar lordosis. Just as lumbar curve, sacral angle and pelvic tilt must all be assessed separately; lumbar curve and thoracic tilt must also be assessed separately. Any combination of these four factors can occur together.
Lumbar lordosis must be assessed with the client standing on a level surface, barefoot. Additional information may be gained by examining posture supine, but supine assessment may never be substituted for standing assessment.
Figure 8. The thorax can sit in many possible ways over the same lumbar curve.
Keep The Client Standing
A final consideration in assessing lordosis is client position. Lumbar curve and any other feature of posture will usually be different when a person is standing, compared to when that same person is supine. In these two positions, the large force of gravity is acting on the body in two different directions at 90 degrees to each other. The interaction of gravity with the internal tensions in the body will produce different--and sometimes radically different--posture in these two situations. To demonstrate this difference, assess both pelvic tilt and lumbar curve in each of your clients this week. Assess both features standing, and then make the same assessments supine. You will find that with most clients there are significant differences between the two assessments. The direction and amount of difference between these two assessments will be different for each person, depending on the extent and nature of internal tensions in the body.
Lumbar lordosis, like all other features of alignment, must be assessed with the client standing on a level surface, barefoot. Additional information may be gained by examining posture supine, but supine assessment may never be substituted for standing assessment.
Several important points, which are summarized below, should be followed when working on a client with lordosis. They include:
- Lumbar curve is best assessed by palpation of the spinous processes of the lumbar vertebrae.
- The spinous processes of the lumbar vertebrae will usually express less than the actual lumbar curve. The amount of apparent difference between these two curves will vary from person to person.
- Soft-tissue contour is often highly misleading. To assess lumbar curve, or any other feature of alignment, bony palpation is necessary.
- To assess the lumbars, assess only the lumbars. Sacral angle, thoracic tilt and pelvic tilt are not features of the lumbars. Assess and note these other features separately.
- Assess functional aspects along with static alignment. Functional considerations take precedence over static alignment.
- Proportions vary from person to person; there is no "one size fits all" perfect alignment.
- Postural assessment must be done with the client standing barefoot on a level surface.
Jeffrey Burch, MS, LLC, is based in Eugene, Oregon. A certified advanced Rolfer, he is in private practice, specializing in visceral manipulation and CranioSacralSM Therapy. He teaches kinesiology and other related courses at Cascade Institute of Massage and Body Therapies in Eugene, and offers continuing education courses to structural integrators. He can be reached at: firstname.lastname@example.org.