The Pelvic Girdle and Hip Joint 191Hip External Rotation
Hip external rotation involves lateral rotation of
the anterior thigh relative to the pelvis about the
mechanical axis of the femur in a transverse plane.
Because of the angulation of the neck of the femur,
the long axis of rotation is not in the shaft of the
femur, but rather medial to it—a line extending
between the centers of the hip and knee joints.
The deep outward rotators and gluteus maximus
are potentially assisted by other hip external rotators
(listed in table 4.4) when contracting concentri-
cally to rotate the legs outward from a parallel first
to a turned-out first position or in the prone passé
or prone frog (table 4.5, M and N, pp. 219-220).
However, more commonly hip external rotation is
combined with other movements of the hip rather
than being used in isolation, such as during the
swing phase of walking, the frog kick in swimming,
or the side leg raise and side leg pull (table 4.5, G
[p. 216] and K [p. 218]) variations performed in
an externally rotated position. Examples of move-
ments from dance that combine hip extension and
external rotation include the back leg of a grand jeté,
an arabesque, or a back attitude as shown in figure
4.28. Hip external rotation would also be used in
any dance movements performed in a turned-out
versus parallel position, and the direction of theThe Trendelenburg Test
Use the Trendelenburg test to evaluate the
hip abductor mechanism on (1) another
dancer and (2) yourself as explained next.- Evaluation of another dancer. Have your
partner stand on the left leg, with the
right hip and knee slightly flexed so that
the right foot clears the floor. Kneel
behind the dancer, and place your right
thumb on the right PSIS and the remain-
ing fingers of the right hand along the
right lateral crest of the ilium. Place
your left thumb on the left PSIS and
the remaining fingers on the left lateral
portion of the crest of the ilium. If these
matched landmarks appear at the same
height, that is, in the same transverse
plane, this is a negative Trendelenburg
sign (A); if the PSIS or crest of the ilium
is markedly lower on the unsupported
side, this indicates a positive Trendelen-
burg sign (B). - Self-evaluation. Stand on one leg (with
the opposite hip and knee slightly flexed
so that the foot is off the ground) in
front of a mirror. Place your right index
finger on your right ASIS and your left
index finger on your left ASIS. If these
landmarks appear at the same height, this is a negative Trendelenburg sign, while if the ASIS is
markedly lower on the unsupported side, this indicates a positive Trendelenburg sign and sug-
gests that hip abductor weakness is present.