When performing a pirouette, women raise onto the toe (pointe) and men balance themselves on the ball of one foot (demi-pointe). Next, one leg is extended out, then bent at the knee to bring the tip of the toes back to the kneecap. This occurs as the dancer whirls in a stationary circle. At the same time, the arms symmetrically are raised to the sides, then brought together, with the fingertips meeting to form a circle.
Hip flexors, muscles that flex the thigh bone toward the pelvis, cause hip flexion near the leg that swings out. These muscles flex the hip joint, which allows the nonstationary leg to be swung away from the pelvis.
Next, plantar flexors in the ankle of the moving leg promote rotation, or vertical spinning, as the ankle is bent to point the toe. This is called plantar flexion. In other words, bringing the foot of the straightened leg back in allows the dancer to spin. As all of this is happening, plantar flexors on the supporting, stationary leg are also engaged. These muscles promote balance as the dancer turns on her toe.
While the nonstationary leg is in motion, knee extensors extend the knee as the dancer first straightens her leg. Then, knee flexors contract as the knee is bent to hold the joint in this flexed position. When pirouettes are performed in a sequence, the knee flexors will contract and extend for each pirouette.