192 Dance Anatomy and Kinesiology
accompanying movement (e.g., front, side, back)
would influence the muscles recruited to produce
the desired hip external rotation.
A reversal of the customary action of the hip
external rotators can also be used to rotate the pelvis
away from a stationary femur. For example, during
standing with both legs fixed, rotation of the pelvis to
the right will result in internal rotation of the right
hip joint and external rotation of the left. This closed
kinematic chain rotation is commonly used in throw-
ing, in swinging a baseball bat or tennis racket, and
in a golf swing. The mechanism is commonly used in
dance for turning, dodging, or change-of-direction
movements in which the thrust of the pushing leg
turns the pelvis in the desired direction.Hip Internal Rotation
Hip internal rotation involves medial rotation of
the anterior thigh relative to the pelvis about the
mechanical axis of the femur in a transverse plane.
The anterior fibers of the gluteus medius and gluteus
minimus are potentially assisted by other hip inter-
nal rotators (listed in table 4.4) when contracting
concentrically to rotate the legs inward in the pronehip internal rotation (table 4.5P, p. 220). However,
as with hip external rotation, hip internal rota-
tion is more commonly combined with other hip
movements such as on the support leg during the
swing phase of walking or in a side kick in karate.
Examples of movements from dance include the use
of an internally rotated position with side lunges or
other stylized movements in jazz or contemporary
dance (figure 4.29). Additionally, a quick internal
rotation of the thigh (with the knee bent) immedi-
ately preceding hip external rotation in a turned-out
side développé is sometimes used as a teaching tool
for helping students to learn to isolate rotation of
the femur in the hip joint without undesired rota-
tion of the pelvis.
A reversal of the customary action of the hip
internal rotators can be used to rotate the pelvis
toward a stationary femur. This closed kinematic
chain internal rotation is used in walking and run-
ning, in which the pelvis rotates toward the support
leg as the other leg swings forward, functioning to
increase stride length. In throwing, striking, and
some dance movements, the initial plant of the for-
ward foot places the forward thigh in lateral rotation.
However, as the athlete comes forward over the foot,FIGURE 4.28 Sample dance movement showing hip external rotation combined with hip extension.
Photograph by David Cooper. Pacific Northwest Ballet School students.