106 Dance Anatomy and Kinesiology
Although a well-balanced “S” scoliosis, even if
involving large curvatures, does not necessarily pre-
clude a professional dance career, it is associated
with an increased risk for stress fractures (Warren et
al., 1986) and low back injury. In the experience of
the author, even many dancers with low curvatures
(especially when accompanied by larger rotations)
experience asymmetry in their work. Hence, par-
ticular attention should be directed toward avoiding
further development of asymmetries, with assistance
procured from a qualified physical therapist if
needed. Furthermore, attention should be paid to
preventative measures for stress factors (including
nutritional and hormonal) discussed in chapter 1.Spinal Mechanics
The fact that the normal spine is comprised of many
consecutive segments with alternating curves influ-
ences its vulnerability to injury and the actions that
muscles can have on it. The abdominals appear to
play a particularly key role in protecting the spine via
mechanisms still under investigation. One example
of how changes in spinal curvature can affect mus-
cles’ action is illustrated with the psoas paradox.Abdominal Contraction for Spinal Protection
The spine can be subjected to tremendous forces
during dance and other athletic endeavors. It has
been calculated that 2,071 pounds (939 kilograms) of
force is imposed on the lumbosacral disc as a person
leans forward and lifts a 170-pound (77-kilogram)
weight off the ground (Morris, Lucas, and Bresler,
1961). Similarly, a study of selected aerobic dance hip
extension exercises (involving motions similar to those
utilized in dance) showed that torque values occur-
ring at the lumbar spine were greater than those that
are estimated to accompany lifting a 100-pound (45-
kilogram) load (Hall and Lindoo, 1985). Such large
forces approach or even exceed the forces found to
damage discs (Bartelink, 1957) or the bony vertebrae
themselves (Eie, 1966) when they are removed from
cadavers and studied in a laboratory setting. The fact
that apparent damage to the spine does not occur
during such rigorous functional activities (despite
meeting or exceeding experimental loads that pro-
duced damage) suggests that in the living organism,
something must serve to protect the spine.
One of the mechanisms that may provide protec-
tion for the spine is intra-abdominal (L. within the
abdomen) pressure (IAP). Intra-abdominal pressureDetection of Scoliosis
Perform the observations and forward bend test on another dancer as described next, using figure
3.30 as a reference. Observation will be easier if female dancers wear a swimsuit top, a halter top,
or a backless leotard and if male dancers remove their shirts.
General Observation
Have your partner stand upright with the legs parallel and feet under the hip joints. Viewing your partner
from both the front and back, note any apparent asymmetries such as a difference in shoulder height,
scapular prominence, unequal height of hands or distance of arms from sides of body, difference in
height of one side of the pelvis versus the other, one side of the pelvis rotated farther forward than
the other, unequal waistline, or leg length discrepancy. Standing from behind, palpate the spinous pro-
cesses from the top of the neck to the sacrum and note any apparent lateral curvature or rotation.
Forward Bend Test
Then, observing from directly behind, have your partner very slowly bend forward (“roll down”), start-
ing from the top of the head, and progress downward while the arms hang free by the sides. Look
for symmetry of the sides of the trunk at each level of the spine and note whether one side is higher
and if there is a “rib hump.”
Note: Although helpful, it is important to realize that many factors such as leg length difference and
handedness patterns can create asymmetries. However, young dancers with apparent scoliosis are best
referred for medical evaluation to determine the basis and magnitude of apparent asymmetries.