“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.