Analysis of Human Movement 495in the early portion of this phase to initiate knee
flexion so that braking forces are minimized and the
tendency for the femur to translate anteriorly on the
tibia (knee shear forces) is lessened (Simpson and
Kanter, 1997; Simpson and Pettit, 1997).
While the landing leg plays the vital role of
controlling the downward motion of the body and
preparing for the ensuing direction of motion of the
body’s center of gravity, the right leg may stay behind
in an arabesque as shown in table 8.7E. With this
variation of a grand jeté en avant, the hip extensors of
the back leg must contract rigorously with an isomet-
ric or slight concentric contraction to prevent the leg
from dropping and to achieve the desired aesthetic
of the arabesque position. The knee extensors work
isometrically to maintain the knee in extension while
the ankle-foot plantar flexors work isometrically to
help maintain the point of the foot.
In terms of stabilization, the complex co-contrac-
tion of the spinal extensors and flexors is again key to
achieve the desired aesthetic of the movement. The
desire is to keep the upper torso relatively vertical
during the flight phase of the movement. Some danc-
ers get an undesired visible flexion and extension
of the trunk during the movement. One reason the
torso often flexes forward is that the pelvis must be
tilted anteriorly to allow the back leg to reach the
desired height. However, as discussed in connection
with an arabesque in chapter 4, the back extensors
can contract to bring the upper torso back to verti-
cal and to prevent the undesired forward motion of
the whole torso.
Anatomical analysis also reveals that extreme
range of motion is required at the hips to achieve
the split position in the air. A quick test that can be
used to help determine if hip flexibility is a limiting
factor is a passive split (Tests and Measurements 8.2).If a split position cannot easily be accomplished,
this suggests that muscular constraints would offer
internal resistance to the desired split position in the
grand jeté, making it more difficult or not possible
to achieve (depending on the extent of limitation).
To more specifically determine the soft tissue con-
straints, tests presented in chapter 4 can be used.
Hamstring flexibility (Tests and Measurements 4.4
on p. 205) can be tested to see if these muscles are
limiting the desired height of the front leg, while
hip flexor flexibility (Tests and Measurements 4.5 on
p. 212) can be tested to see if these muscles are limit-
ing the desired height of the back leg.
Analysis of the grand jeté also reveals that there are
high strength demands for the hip extensors, knee
extensors, and ankle plantar flexors of the takeoff leg
(right leg) to overcome the weight of the body and
project the body in space during the takeoff phase.
As with running, the greater the force generated by
the body against the floor at takeoff, the greater the
ground reaction force that will propel the body, and
the greater the acceleration of the body. During the
flight phase, moderate levels of hip flexor strength
are needed to lift the lead leg, and moderate levels
of hip extensor strength are needed to lift the back
leg to the desired split position. During the landing
phase, there are high strength demands on the sup-
port leg (left leg) of the hip extensors, knee exten-
sors, and ankle plantar flexors in order to decelerate
the body and absorb the large forces associated with
landing. A preliminary investigation of three elite
ballet dancers found vertical maximum forces of
approximately 3 to 6 times body weight associated
with landing from a grand jeté devant (Clippinger
and Novak, 1981).
In terms of technique considerations, one
common error in beginning dancers is to not achieveMovement phases
and selected joints Joint movements Contraction type Prime movers: muscle group (sample muscles)
Landing phase: E
Left hip Hip flexion Eccentric Hip extensors (hamstrings, gluteus maximus)
Left knee Knee flexion Eccentric Knee extensors (quadriceps femoris)
Left ankle-foot A-F dorsiflexion Eccentric and passive
as body moves
forward over foot
A-F plantar flexors (gastrocnemius, soleus)Right hip Hip extension Concentric Hip extensors (hamstrings, gluteus maximus)
Right knee (Knee extension
maintained)
Isometric Knee extensors (quadriceps femoris)Right ankle-foot (A-F plantar flexion
maintained)
Isometric A-F plantar flexors (gastrocnemius, soleus)