204 Dance Anatomy and Kinesiology
FIGURE 4.36 The side extension.
Photograph by Rex Tranter. Pacific Northwest Ballet School students.knee is straight, the hamstrings are stretched across
the back of both the hip and knee, and hip flexion
can proceed passively only as far as extensibility of the
hamstrings will allow. A screening test can be utilized
to evaluate hamstring flexibility (Tests and Measure-
ments 4.4). If hamstring flexibility is low, emphasis
should be placed on stretching the hamstrings (table
4.7, C and D, p. 225) as well as strengthening the hip
flexors. If hamstring flexibility is high, this suggests
that the limiting factor is more hip flexor strength and
perhaps more specific activation of the iliopsoas.
When lifting the leg to the front in a turned-out
versus parallel position, another consideration comes
into play. Many dancers have difficulty maintaining
external rotation as leg height is increased. This is
logical for two reasons. First, the DOR become less
effective in their ability to produce external rotation,
and the upper DOR (the piriformis) may actually
switch its function to become an internal rotator in
high ranges of hip flexion (Smith, Weiss, and Lehm-
kuhl, 1996). Second, the anterior fibers of the gluteus
medius, gluteus minimus, and tensor fasciae latae
increase their leverage for hip internal rotation as the
hip is flexed. So, while when the hip is in extension
the maximum torque for internal and external rota-
tion is about equal in the general population, when
the hip is flexed the maximum torque generated by
the hip internal rotators is increased about three
times. To counter this problem, it is important that
dancers develop greater strength in the hip external
rotators and specifically in the lower DOR that are
still in a position to produce hip external rotation.
Focusing on bringing the greater trochanter “down
and under” can often help achieve the desired activa-
tion of the quadratus femoris.Extensions to the Side
Extensions to the side are one of the measures of
skill used for selection of dancers in the professional
ballet arena (figure 4.36), and many dancers strive
to increase their height. The use of turnout in this
position produces a unique situation in which the
anterior surface of the thigh is moving in a frontal
versus sagittal plane, a hybrid between hip flexion
and hip abduction. Although research will be nec-
essary for better understanding of the interplay of
muscles in this action, EMG studies and study of the
line of pull of the muscle suggest that the iliopsoas
as well as the hip abductors are key in higher ranges
of hip abduction. As hip abduction progresses, the
distal iliopsoas slides over to the lateral side of the
center of rotation of the hip joint and is thus posi-
tioned to be capable of producing hip abduction.Hence, strengthening the hip flexors and developing
greater activation of the iliopsoas as just described
with extensions to the front can improve movements
such as extensions to the side.
In addition, proper mechanics play a fundamen-
tal role in optimizing leg height. When the thigh is
kept parallel or in medial rotation, range of motion
is limited to about 45° abduction in general popula-
tions, probably due to impingement of the greater
trochanter on the superior rim of the acetabulum and
nearby ilium. However, if the leg is externally rotated
such that the greater trochanter rotates inferiorly, it
will no longer impinge, and the range of hip abduc-
tion is tremendously increased. So, greater external
rotation will allow a greater range of hip abduction
to be achieved (Kushner et al., 1990), and use of this