30 Dance Anatomy and Kinesiology
“Stand So That Your Bones Support Your Weight”
S
ome forms of modern dance encourage students to achieve standing alignment emphasizing
support by bones and minimizing muscle contraction to maintain an upright position. Although
standing involves many joints, for simplicity we focus on the knee at this point. During standing with
the knees straight, a close-packed position of the knee is present, allowing the bones and passive con-
straints to primarily create stability. However, if the knees are bent either in a standing position or to
begin a movement, muscle contraction is immediately required to prevent the knees from buckling.
While some schools of dance that emphasize efficiency favor this cue and a more passive approach
with standing, other schools prefer a more active stance (“pulling up on the knees”) utilizing slight
levels of muscle contraction as discussed in chapter 5.DANCE CUES 1.2
of rigid links are interconnected by a series of pin-
center joints such that motion of one link will pro-
duce predictable motion in the other joints of the
system (Levangie and Norkin, 2001). In the human
body, a kinematic chain (G. kin ̄ematica, things that
move) is represented by a series of joints that link
successive body segments or bones. The concept of
a closed kinematic chain, or closed kinetic chain, is
operative when the distal segment is fixed while the
proximal segments move, such as when one is in an
erect weight-bearing position. In this case, when
the knee bends, simultaneous motion in the ankle
and hip also occurs. In contrast, when the distal seg-
ment moves in space, such as in performing brushes
(dégagés), motion at the hip can occur in isolation,
without necessarily involving motion of the knee. This
is termed an open kinematic chain, or open kinetic
chain, movement. With this type of movement, the
motion of adjacent joints is not predictable, as they
may move either independently or together.
In dance, the upper extremity is more commonly
used in an open kinematic chain manner such as
when the dancer is making gestural movements.
However, when used in an open manner, there is
often a required linking of segments to achieve the
desired aesthetic for use of the arms. This aesthetic
often varies markedly between different dance forms
and even different choreography within the same
dance form. Less frequently the arms are used in
a closed kinematic manner, such as when one isperforming weight-supported positions like a hand-
stand. In dance, the lower extremity is commonly
used both as a closed and as an open kinematic
system, often changing in different phases of the
movement or between sides of the body. An example
of the former is in a stag leap: Prior to the takeoff the
lower extremity is working in a closed manner, while
in the air the legs are acting as an open kinematic
chain. An example of the latter occurs at the barre;
the support leg is working in a closed manner, while
the gesture leg is often working as an open kinematic
chain as seen in figure 1.17.
The concept of kinematic chains has important
implications for understanding movement, injury,
and rehabilitation. In terms of movement, one
important implication has to do with the potential
movement allowed by the whole limb. The total
degrees of freedom available for the performance of
a multijoint movement is considered the summation
of the degrees of freedom derived from all adjacent
joints in the chain. So, for example, kicking a ball
could be considered to involve an 11-degree-of-
freedom system relative to the trunk, with 3df derived
from the hip, 2df from the knee, 1df from the ankle,
3df from the tarsals, and 2df from the toes (Hamill
and Knutzen, 1995). This summation concept is
essential to allow for the complex movements and
adjustments required by dance. Implications for
injury and injury rehabilitation is addressed in fol-
lowing chapters.