Dance Anatomy & Kinesiology

188 Dance Anatomy and Kinesiology

kept in a relatively neutral (extended) position, and

the trunk moves as a unit about the hip axis versus the

sequential flexion of the spine generally used in the

curl-up. More dramatic examples of this simultane-

ous movement of the trunk and thigh occur with “V”-

sit or teaser types of movements (previously shown

in figure 3.43 on p. 129) in modern, jazz, or Pilates.

Such advanced exercises require high strength and

skill levels so that abdominal co-contraction can be

used to help stabilize the low back and pelvis in order

for the hip flexors to bring the thighs and trunk

together without undesired and potentially injurious

arching of the low back.

However, when hip flexion occurs while the lower

limb is weight bearing (closed kinematic chain move-

ments), gravity will tend to create further hip flexion

once a small amount of hip flexion is produced. So

it is actually the hip extensors that are primarily used

eccentrically to control hip flexion and prevent col-

lapse of the body to the ground. Examples of this type

of hip flexion occur on the down-phase of a parallel

plié, in the landing phase of a parallel jump, or when

one brings the trunk forward in a roll-down or to a

flat back position.

Hip Extension

Hip extension is a movement in a posterior direction

such that the angle between the posterior surfaces

of the articulating bones decreases. The hip exten-

sors—the hamstrings and gluteus maximus—per-

form their customary open kinematic chain action

when contracting concentrically against gravity or

resistance to move the femur backward in the back

leg raise (table 4.5D, p. 214), in the kneeling ara-

besque (table 4.5E, p. 215), or in running (recovery

phase). In dance, one uses this type of hip extension

when moving the leg to the back with a leap (back

leg), tendu, dégagé, back développé, back attitude,

or arabesque penché as seen in figure 4.25.

When the foot remains fixed and in contact with

the ground (closed kinematic chain movements), hip

extension occurs against gravity when straightening

from a flexed position, such as on the up-phase of

a squat, plié, or jump or when bringing the trunk

back to a vertical position from a flat back position.

Concentric hip extension is also used in locomotor

movements to bring the weight of the body over the

foot, and posturally to create a posterior pelvic tilt,

while isometric hip extension is used to maintain

FIGURE 4.24 Hip flexion involving movement of the anterior

surface of one femur and the pelvis toward each other.

FIGURE 4.23 Sample dance movement showing hip

flexion.

Photo courtesy of Myra Armstrong. Dancer: Lorin Johnson with American Ballet

Theatre.