Spinal Curvature and Orthotic Support
by Brian Jensen, DC
Chiropractors frequently treat curvatures of the spine. Unfortunately, a lateral curvature of the spine is
often identified as a “scoliosis” and referred to surgeons for care. While a small fraction of lateral
curvatures has a tendency to progress and to require surgical consultation, most are easily treated with
conservative methods. Too often, non-structural and non-idiopathic causes of spinal curvatures are
overlooked, and their proper treatment is ignored. This can leave a patient with persisting postural
distortions, as well as recurring subluxations. Over time, asymmetric degenerative changes and vertebral
deformities frequently develop. With just a few specialized tests during the clinical examination, many
of the lateral spinal curvatures seen in both children and adults can be correctly identified and effectively
managed with conservative chiropractic care.
Lateral Curvature Definitions
There are many possible causes of a lateral curvature, and this condition can affect the cervical, thoracic,
or lumbar regions. A lateral deviation is called a scoliosis, which is defined as “any lateral deviation of
the spine from the mid-sagittal plane.” (1) The most common types of scoliosis seen by doctors of
chiropractic can be divided into structural and functional (or “non-structural”) categories.
Structural scoliosis. When the lateral deviation of the spine is fixed, and cannot be corrected during
lateral bending, it is termed a structural scoliosis. While there are many disorders that can cause this
condition, the most commonly seen are neuromuscular (associated with various neuropathic and
myopathic diseases), congenital (due to bony anomalies), and idiopathic (where the underlying cause is
unknown). Most of these spinal curvatures do not respond well to conservative care, are frequently
progressive, and often require a surgical consultation.
Functional scoliosis. The causes of non-structural scoliosis are also many, but these will usually respond
well to appropriate non-surgical care. The classification of functional scoliosis has been summarized as
compensatory (due to leg length inequality or pelvic unleveling), postural (caused by habits and muscle
imbalance), and transient (often an antalgic response to a disc herniation). (2) The key factor in all of
these conditions is the reversibility of the abnormal curvature with various positions and movements.
This is one of the main methods used in the differentiation between structural and functional types of
scoliosis.
Evaluation of Lateral Curvatures
Adams forward bending. The fastest way to evaluate a lateral spinal curvature is to use the Adams
position test. The patient flexes forward from the waist, with the arms hanging down and the hands
together. If the spinal curvature straightens out and there is no evidence of rib humping, then the test is
considered to be negative, and it indicates a functional scoliosis. (3) A similar phenomenon can also be
noted when the patient lies prone on the examination table. If the curvature is functional, then it will
disappear as the muscles relax and the spine no longer depends on the lower extremities and pelvis for
support. This is most obvious in younger patients, since the spine becomes less flexible with age, and
functional curves become stiffer and more fixed.
Postural assessment. When examining a patient with a spinal curvature, the first step is to carefully
inspect the alignment of the entire body during relaxed, upright stance. Note the head position in relation
to the body, relative heights of the shoulders, and any spinal list or rotation, since corrective exercises
may be needed. The lower extremities must be evaluated for any asymmetry, because functional
scolioses are commonly associated with leg length inequality. (4) Most commonly seen is pronation of
one or both of the feet.
2
Hyperpronation. The loss of arch height that occurs with excessive pronation allows the pelvis to drop to
the more pronated side during stance and gait. The resulting lateral pelvic tilt lowers the sacral base and
drops the lowest freely moveable vertebra to the side of the shorter leg. A lateral spinal curvature
develops in the lumbar spine due to lack of balanced support from the lower extremities. If the
functional curvature progresses to involve the thoracic region, it may demonstrate a mild rib hump, which
disappears upon correction of the leg discrepancy.
Researchers have also verified that a posterior rotation of the innominate then develops on the side of a
longer leg. (5) In persons with asymmetrical pronation, the accentuated medial rotation movement of one
leg is transmitted to the pelvis and sacroiliac joints. In response, various compensatory pelvic lists and
sacroiliac subluxation complexes have been found to develop. (6)
Corrective Action
Spinal adjustments. Since excessive pronation places abnormal stress in predictable areas (especially the
sacroiliac joints and lumbar vertebrae), close evaluation of these regions will be needed. And because a
lateral curvature generally interferes with postural alignment, the entire spine must be checked and
adjusted frequently during the initial period. In fact, the upper cervical region is often quite slow in
adapting to the change in spinal and pelvic posture, and needs to be carefully adjusted.
Lower extremity support. A very common cause of a functional lateral curvature is pelvic asymmetry
and/or a leg length discrepancy due to a low medial arch and excessive pronation. In both of these
conditions, there is no possibility of improving spinal alignment without treating the feet. The use of
custom-made, stabilizing orthotics to reduce pronation can provide substantial correction for most short
legs, without the need for a heel lift. It is very important to recognize this cause of a short leg, since
providing a lift instead of an orthotic is likely to perpetuate the associated sacroiliac subluxations. In
some patients, a permanent heel lift is needed, due to an anatomical difference in growth of the legs.
References
1. Yochum TR, Rowe LJ. Essentials of Skeletal Radiology, 2nd ed. Baltimore: Williams & Wilkins,
1996:307.
2. Panzer DM, Fechtel SG, Gatterman MI. Postural complex. In: Gatterman MI, ed. Chiropractic
Management of Spine Related Disorders. Baltimore: Williams & Wilkins, 1990:278.
3. Evans RC. Illustrated Essentials in Orthopedic Physical Assessment. St. Louis: Mosby-Yearbook,
1994:219.
4. Plaugher G. Textbook of Clinical Chiropractic: A Specific Biomechanical Approach. Baltimore:
Williams & Wilkins, 1993:266.
5. Cummings G, Scholz JP, Barnes K. The effect of imposed leg length difference on pelvic bone
symmetry. Spine 1993; 18:368-373.
6. Rothbart BA, Estabrook L. Excessive pronation: a major biomechanical determinant in the
development of chondromalacia and pelvic lists. J Manip Physiol Therap 1988; 11:373-379.
About the Author
Dr. Brian Jensen is currently the Associate Director of Professional Education at Foot Levelers. He
speaks on a wide variety of topics, including orthotic therapy, posture, structural preservation, breaking
free of the medical model of health care, and innovations in nutrition. Dr. Jensen can be reached at
1.800.553.4860.