“It is a dancer’s responsibility to know the parts of her
instrument and study how they work in unison to create a beautiful work of
art.”
Understanding
the different parts of the body and how they work is an essential part of dance
training. Physical activities, like
dance, require a thorough knowledge of the instrument in order to produce the
best possible performance.
Skeletal
bones are the body’s foundation, but they require muscles to hold them securely
together and to allow for movement. Muscles
are organs that are composed of thousands of individual fibers. These fibers have four important
qualities: excitability, contractility,
extensibility and elasticity.
Excitability means that muscles are able to receive stimuli, or
messages, from the nervous system and react to them through movement. When a muscle receives a signal to move, it
contracts, or shortens, to pull on the bone to which it is attached. The abilities to shorten and exert a force and
to release afterward are contractility and extensibility. Muscles are also capable of being
stretched. Elasticity is the quality
that allows the muscle to return to its original length after being stretched.
In order
for muscles to move the skeleton, they must be connected to the bones by
tendons. Tendons are thick bands of
tissue that can be stretched and, like muscles, are elastic and will return to
their original length. Studies have
shown that tendons respond to forces like muscles do, and when they are used
repeatedly, they will also grow stronger.
A recent study published by The Proceedings of the Royal Society in
March 2012, showed that, in addition to connecting muscles to bones, tendons
act as shock absorbers. When a dancer
lands a jump, it is the tendon that absorbs the primary shock and not the
actual muscle. Resultantly, the tendon
is also thought to act as a spring and provide recoil strength after landing.
While
tendons connect muscles to bones, ligaments connect bones to each other. The main purpose of a ligament is to limit or
prevent certain movements. The knee
joint is one joint in the body where ligaments predominate. The medial (inside) and lateral (outside)
collateral ligaments limit sideways motion of the patella, or kneecap, while
the posterior cruciate ligament prevents the knee from bending backwards. Ligaments do not possess the same amount of
elasticity that muscles and tendons do.
Once a ligament is stretched forcibly or for an extended period of time,
it will not return to its original length and may require surgery. It is for this reason that a bone dislocation
should be cared for as soon as possible to prevent permanent ligamental damage. Some people are born with
extremely loose ligaments and are incorrectly labeled “double-jointed”.
Knowing the
body and how each part functions helps dancers to understand how to get the
most from their training, understand how to care for injuries if they happen
and learn how to optimize their performance.