The Spine 95many spinal structures, including the portion of the
vertebrae (pars interarticularis) commonly involved
in stress fractures (spondylolysis). In addition to
increased shear, fixed hyperlordosis is associated with
greater contraction of the erector spinae (Frankel
and Nordin, 1980; Wolf et al., 1979), which may allow
low back muscle fatigue and strain to occur more
readily. Furthermore, fixed lordosis can interfere
with the cyclic loading and unloading of the facet
joints necessary for proper cartilage nutrition, which
may precipitate early breakdown of this cartilage
(Stanish, 1979).
Lumbar hyperlordosis is often prevalent in young
dancers and is sometimes exaggerated in an effort to
achieve greater turnout. However, at least in ballet,
lordosis may decrease with years of training. Dance
training encompasses alignment directives that
may tend to create straighter cervical, thoracic, and
lumbar curvatures. One study of young ballet danc-
ers showed that although lumbar range of motion in
extension was higher, the depth of lumbar lordosis was
significantly lower in dancers than in age-matched
non-dancers (Livanelioglu et al., 1998). Similarly, in
another study of ballet dancers, lumbar hyperlordosis
was very prevalent in Level 1 dancers but not in Level
6 or advanced/company dancers (Clippinger-Rob-
ertson, 1991). In contrast, in higher levels of dance,
fatigue posture was prevalent. So, it is important for
dancers to realize that having hyperlordosis at one
point in training does not mean that this will always
be a problem, and care must be taken not to overcor-
rect and excessively reduce the lumbar curve.
When lumbar hyperlordosis is present, strength-
ening the abdominal muscles (figure 3.25A and
table 3.4 [p. 134]) can often help improve the
condition. Posteriorly, the spine forms a bony con-
nection between the rib cage and pelvis. However,
in the front, this connection is effected purely by
the abdominal musculature. Because of this struc-
ture, the strength, resting length, and activation
of the abdominal musculature are very critical in
determining the distance between the rib cage and
pelvis. That distance, in turn, affects the curvature of
the lower spine and hence ideal alignment as seen
in figure 3.24.
In addition to inadequate abdominal strength,
lumbar lordosis may also involve low back and hip
flexor (especially the iliopsoas) tightness as seen
in figure 3.24A. Excessive lordosis associated with
muscle tightness is particularly common during
adolescent growth spurts (Micheli, 1983). If this is
the case, stretching of the hip flexors (figure 3.25B
and table 4.7A [p. 224]) and low back (figure 3.25C
and table 3.7, A and B [p. 144]) will also be necessarythe pelvis is vertical (ASIS in a vertical plane with the
pubic symphysis; see chapter 4) rather than tilted
forward or backward. This positioning of the pelvis
will directly affect spinal alignment, as an anterior
pelvic tilt tends to increase the lumbar curve while
a posterior pelvic tilt tends to decrease the lumbar
curve. Positioning of the spine and pelvis also affects
alignment of the lower extremity and can contribute
to such alignment deviations as hyperextended knees
(genu recurvatum) and rolling in of the feet (prona-
tion), discussed in later chapters of this text.
The body can also be viewed relative to a vertical
plumb line from the front or the back. When one
views the dancer from behind, the gravity line should
bisect the distance between the heels and ideally be
in line with the spinous processes of the vertebrae.
When viewing from the front, the gravity line should
again bisect the distance between the feet and ideally
be in line with midline structures such as the pubic
symphysis, umbilicus, and nose. These anterior and
posterior views provide the opportunity to see asym-
metries between right and left sides of the body such
as is associated with scoliosis.
Lumbar Hyperlordosis
In the normal upright stance the sacrum tilts anteri-
orly and inferiorly an average of about 30° (normal
lumbosacral angle). This tilt necessitates that the
lumbar spine extend (termed lordosis) in order to
bring the torso upright (figure 3.23A), giving rise to
the normal lumbar curve. However, in some individu-
als there is an abnormally large lumbar curvature.
This postural condition is termed lumbar lordosis
(G. lordosis, a bending backward), or more accu-
rately lumbar hyperlordosis (figure 3.23B). Lumbar
hyperlordosis is often accompanied by an increased
inclination of the sacrum (increased lumbosacral
angle), an anterior pelvic tilt, and sometimes a for-
ward displacement of the torso relative to the ideal
posture plumb line.
Lumbar hyperlordosis not only is undesirable
from a perspective of the aesthetics of many dance
forms but also may increase the risk for low back
injury (Goldberg and Boiardo, 1984; Ohlen, Wred-
mark, and Spangfort, 1989). First, lumbar lordosis
increases the tendency for the lower vertebrae to
slide forward on the underlying vertebrae (shear
forces). For example, inclining the sacrum forward
10° or 20° is associated with an increase in the shear
force acting across the lumbosacral joint from 50%
of body weight to 65% or 75% of the body weight
above this joint, respectively (Hamill and Knutzen,
1995). This increased shear produces extra stress on