Dance Anatomy & Kinesiology

166 Dance Anatomy and Kinesiology

Posturally the iliopsoas plays an important role in preventing the torso from falling backward and may

help maintain the lumbar curve. The former role is key when one is performing floor work in modern

dance, and many dancers who are unaccustomed to floor work may find themselves getting fatigued

and sore in the hip flexors, particularly the iliopsoas. Some also hold that the iliopsoas may play an

important role in integrating and coordinating movements between the femur, pelvis, and spine.

Attachments and Primary Actions of Rectus Femoris

Muscle Proximal attachment(s) Distal attachment(s) Primary action(s)

Rectus femoris

(REK-tus FEM-o-ris)

Anterior inferior iliac spine

Posterior head: just above acetabulum

Tibial tuberosity via patellar

tendon

Hip flexion

(Knee extension)

Rectus Femoris

The rectus femoris, shown in figure 4.6, is one of the four muscles

that make up the quadriceps femoris. It is the only member of

the group that crosses the hip joint. The other three muscles

attach distally relative to the hip joint and act only on the knee.

“Rectus” means straight, so as its name implies, the rectus

femoris runs straight down the front of the femur or thigh. In

addition to its action of flexing the hip, the rectus femoris muscle

also extends the knee. Its combined movement of hip flexion and

knee extension used with kicking has given rise to its being called

the “kicking muscle.”

Palpation: Sit in a chair with the left foot crossed over the right

ankle. Place your fingertips on the center of the upper portion of

your right thigh, and feel the rectus femoris tighten under your

fingertips as you attempt to extend your right knee while your left

leg prevents this motion.

Sartorius

The sartorius is the longest muscle in the body. This slender

muscle runs from the front of the pelvis down the thigh obliquely

and medially to attach on the inside of the tibia as seen in figure

4.6. In addition to assisting with hip flexion, the sartorius can

also abduct and externally rotate the hip. Since this combination

of joint motions is used to assume the crossed-legged sitting

position on the floor, used by tailors in the past, the sartorius (L.

sartor, a tailor) is commonly called the “tailor’s muscle.” These

combined motions are also commonly used in dance vocabulary

such as a passé. Due to its long, thin composition, the sartorius

is designed for speed rather than strength, which may contribute

FIGURE 4.6 The rectus femoris, sarto-

rius, and tensor fasciae latae muscles

(right hip, anterior view).

Attachments and Primary Actions of Sartorius

Muscle Proximal attachment(s) Distal attachment(s) Primary action(s)

Sartorius

(sar-TOR-ee-us)

Anterior superior iliac spine

(ASIS) and area just below

Medial surface of upper tibia

(pes anserinus)

Hip flexion

Hip abduction

Hip external rotation

(Knee flexion)