Demi-Plié (pli, fold [French]). (Fig. 29.3A). This movement may take place in any of the five basic positions on both or one leg. The knees, hips, and ankles are flexed, and the full foot rests on the floor. This lowers the center of gravity, stretches the soleus component of the triceps surae, and thus prepares for air work. It involves concentric contraction of the hip flexors, abductors, and external rotators. There is concentric contraction of the hamstrings at the knee and concentric contraction of the dorsiflexors of the foot and toes. The hip adductors and proximal hamstrings contract eccentrically. Contraction of the quadriceps (except the rectus femoris at the hip) and the peroneus longus, tibialis posterior, and flexor hallucis longus is also eccentric. The depth of the demi-plié is limited by the tension in the soleus muscle and by the abutment of the anterior margin of the distal tibia on the neck of the talus. The patella is compressed against the femoral trochlea. In a properly executed demi-plié, the center of gravity moves directly downward through the legs, the knees passing directly over the feet in the same plane.

Grande-Plié (Fig. 29.3B). In this movement, the center of gravity descends further. The amount of flexion at the knees, hips, and ankles is increased, and the heels are finally lifted from the floor. Extreme stress is put on the knee, particularly components of the patellofemoral and medial tibiofemoral compartments.

Relevé (Fig. 29.3C). While the plié is a vertically downward movement of the center of gravity, the relevé facilitates ascent of the center of gravity, at the same time shifting the body weight to the ball of the foot (in the case of advanced or professional female ballet dancers, to full pointe). It requires active concentric contraction of the long plantarflexors of the foot, toes, and ankle, and also of the quadriceps, because it is usually executed with the knee extended. There is simultaneous eccentric or lengthening contraction of the hamstrings. The deep external rotators and the glutei concentrically contract to stabilize turnout throughout the movement. The adductors eccentrically lengthen to allow for abduction at the hip.

Pointe. Unless a dancer is an aspiring professional female ballet dancer, she will infrequently confront this position. Nevertheless, full pointe is the end point of the relev. In the presence of a long posterior process of the talus or os trigonum tarsi, this position is difficult to attain and is painful in the posterior triangle. There is less strain on the triceps surae en pointe than in relev to half-toe. Ankle stability with the foot en pointe is provided by the flexor hallucis longus and posterior tibial and peroneal (stirrup) muscles.

Tendu (Battement Tendu) (Fig. 29.3D). This movement is a sequential plantarflexion of the foot as it slides along the floor, until only the tips of the toes remain in contact. (The heel leads the movement until it is forced to release from the floor.) The leg remains straight, with active eccentric contraction of the hamstrings. The leg returns to its starting position in a reverse sequence. (When the same movement is performed with the foot brushing off the floor, it is termed dégag, meaning to disengage.) These movements are executed also to the side and back and are essential elements of the ballet barre.

Développé (Fig. 29.3E). This movement is almost always performed with full outward
rotation at the hip. The thigh folds into 90 degrees of flexion at the hip. Simultaneously, the knee also flexes and the foot is drawn up the medial aspect of the standing leg to the knee. Retaining hip flexion, the knee is then extended fully, either to the front, side, or back. Développé front requires active concentric contraction of the hip flexors, in particular the iliopsoas and the rectus femoris. Of primary importance is the sartorius, whose concentric contraction assists in flexion at the hip joint, flexes the knee, and outwardly rotates the thigh during the preparatory action. The hamstrings first concentrically contract to flex the knee, and then eccentrically lengthen during the extension of the leg, as do the gluteals. The external rotators contract to maintain the outward rotation, both on the supporting leg and also on the gesturing leg.

Grand Battement (Fig. 29.3F). This is often referred to by the dancer as an extension and involves simultaneous flexion of the hip to at least 90 degrees with the knee maintained in extension. This movement is usually performed with some speed but may also be done slowly. It is essentially an amplified tendu and dégag, passing through these two movements with the leg sweeping straight up. Proper execution requires concentric contraction of the hip flexors, particularly the iliopsoas and rectus femoris. The quadriceps contract concentrically to straighten the knee, and the triceps surae, tibialis posticus, flexor hallucis longus, flexor digitorum longus, and peroneals do likewise to plantarflex the foot. There is simultaneous lengthening of the hamstrings. Like the développé, this movement may be executed to the front, to the side, and to the back.

This may be a good time to introduce dance speak. When a dancer says I have a great extension, he or she means that the range of hip flexion with the knee extended is unusual. When a dancer speaks of a foot being flexed, it refers to dorsiflexion. Plantarflexion is referred to as pointing or extending. Pointing, combined with excessive lateral deviation of the forefoot, is referred to as winging, or sickling out. This represents a technique defect, as does its opposite (sickling in) (7,10,12).

Arabesque (Fig. 29.3G). This beautiful, graceful, and extremely difficult position is characterized by carrying the leg, which is fully extended at the knee, past 90 degrees posteriorly. The foot is pointed and the hip is fully extended in a position in which the iliofemoral ligament is most taut. The lumbosacral junction must be hyperextended, and there is marked torsion of the pelvis on the spine. On the supporting side, the knee is straight (unless plié is performed), and the foot is parallel to the pelvis. This is an extremely difficult position to attain and sustain, requiring concentric contraction of hip external rotators to maintain outward rotation on both legs. The hip flexors, including the rectus femoris, must eccentrically lengthen across the coxofemoral joint, while the latter joint, with the other quadriceps, must concentrically contract to extend the knee, while the hamstrings and gluteals contract concentrically at the hip. The hamstrings must lengthen across the back of the knee. Technique faults are recognized by excessive pelvic torsion and/or failure to keep the knee of the gesturing leg fully extended and the foot pointed.

Attitude (Fig. 29.3H). The path out to this position is similar to that of développé, except that full extension of the leg does not occur. Rather, the dancer reaches a point at which the leg is held with the hip flexed greater than 90 degrees and the knee flexed 90 degrees. This position can also be reached from grande battement, or from any other movement, and may be executed to the front, side, or back.

Pirouette or Tour (including fouett, attitude, etc.; Fig. 29.3I). These are turns executed on one foot usually beginning from a demi-plié in one of the five basic positions. The weight is then shifted over the ball of the foot of the supporting leg, simultaneously moving into relevé, beginning the
turn, and positioning the gesturing leg. The execution of the turn depends on how centered the dancer is over the supporting leg. This, in turn, is largely dependent on the strength and development of the stirrup muscles, that is, the flexor hallucis longus, flexor digitorum longus, and the tibialis posterior medially, and the peroneus longus and brevis laterally.

Jumps (Fig. 29.3J). Whether off one or both feet, the preparatory position for all jumps is the demi-plié. The higher the jump, the deeper the plié must be. Powerful contractions of the gluteus maximus extend the thigh and the hip; the quadriceps femoris extends the knees, and the triceps surae and other plantarflexors point the feet and toes. In landing, the dancer passes through the ball of one or both feet, releasing the lower extremities into flexion moving back into demi-plié.