Download The dancer in training

The dancer in training
Strength
Learning outcomes
By the end of the lesson:
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Students will understand how to increase
strength.
Learn major muscles and their function in
dance.
Recognise dance injuries.
What is strength?
Strength is the capacity to exert a muscle
contraction against resistance.
Contraction is the opposite muscle action to
that of stretching.
A strong body moves freely, efficiently and
above all safely.
The aim is all-round strength, not the over
development of certain muscle groups.
Types of strength
During exercise, there are two types of
strength:
Isotonic
Isometric
Isotonic
This involves a dynamic resistance during
which the muscle changes in length.
Isotonic work may be either;
Concentric – muscle shortens to produce a
movement e.g. hip abductors of the gesturing leg
as it is raised to the side
 Eccentric – muscle lengthens with tension to allow
movement e.g. hip abductors of the gesturing leg
to control lowering it to the ground
Exercises may be performed, in the full range of
motion of a joint, in sets of 10 to 15. Reps slowly
build to 2 or 3 sets.
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Isometric
This involves static resistance during
which the muscle tension increases but
does not shorten e.g pushing against a
wall or in dance terms; when a leg is
raised to the side, holding it there
means that the hip abductors have an
isometric contraction to resist gravity.
Generally to increase the strength of a
muscle, it must be overloaded. The
dancer strives for an increase in
strength and co-ordination by
perfecting class exercises thereby
improving general technique and
developing speed.
We can overload muscles to build
strength this involves changing:
Frequency: increase the number of
repetitions or speed of a movement.
Intensity: adding more and more resistance,
as with weights.
Duration: increasing the length of time a
movement takes.
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For example: holding a leg off the floor against
the pull of gravity, will build up strength and
stamina in the quadriceps. With added
progressive overload the muscle size and strength
will increase.
Muscles
Muscles are the ‘meaty’ part of the
body. In dance, it is the skeletal muscle
that is of concern.
Muscles are attached by tendons to the
bone at each end
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(a) the end of the origin – this stays still;
(b) the insertion – the end which pulls and
moves.
The quality of the physical condition of
the muscle depends on 5 factors.
Tone or degree of firmness
Freedom from fatigue
Store of readily available nutrients
Temperature
Ability to recover from work
Training influences each of these factors.
Muscle development is associated with size,
strength and endurance. Increase in strength
is measured by an increase in the power of
contraction.
Endurance in a muscle means its ability to
delay the onset of fatigue and the efficiency
of respiratory and circulatory systems greatly
assists the muscles ability to endure work.
Another factor which increases the
effectiveness of trained muscles is better
neuromuscular co-ordination, an increased
skill in movement with elimination of
unnecessary muscle work. This co-ordination
is developed through persistent training and
practice.
So how do we move?
Muscles can only pull (ie contract), and
movement is brought about by pulling
on the bone so as to turn these bones
into levers. The structure of each such
lever has 3 main parts:
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The load or weight
The Fulcrum (balance point) of the joint
The muscle action producing the effort at
the point of the muscle insertion.
Types of lever
There are 3 types of lever
First order
 Second order
 Third order
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Third order lever
Which is the most common?
The most common is the third order
lever.
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The ‘effort’ moves a shorter distance than
the ‘load’.
This has the advantage of allowing a large
movement to be made with only a slight
contraction/shortening of the muscle, thus
making it a more efficient movement.
Muscle contractions
Contraction occurs when muscle fibres
shorten and movement is produced.
This is concentric contraction (as in
contraction of the biceps).
Muscles also produce eccentric
contraction – to straighten the elbow
the biceps brachii muscle fibres will
lengthen.
How do they work in dance?
A plie begins with the pull of gravity, as
controlled by an eccentric contraction of
the quadriceps. Then when the quads
and hip extensors contract
concentrically, the body is raised against
gravity back to standing.
Anatgonists
To dance without injury, a muscle needs
a high level of efficiency in the
antagonistic action of its pair muscle.
This means that while a muscle is
contracting, its opposite muscle must
relax smoothly.
Muscle pairs
Biceps (front upper arm) and triceps (back
upper arm)
Rectus abdominis (front torso) and the long
muscles of the back
Tibialis anterior (front lower leg) and
gastrocnemius, soleus (back lower leg)
Thigh adductors (inside thigh) and gluteus
medius and others (outside thigh)
Quadriceps and hamstrings
Injuries – muscles and tendons
The stronger the dancer the less the
risk of injury, e.g. stronger hamstrings
may reduce the risk of lower back
injuries.
Injuries to muscles and
tendons
Both muscles and tendons are liable to
injury.
If a tendon is irritated by overuse,
tendonitis may occur (usually in the
achilles in dancers).
Muscles are usually injured by a sudden
movement or weak muscles from poor
technique or overuse.
Achilles tendonitis
The symptoms are tenderness and
crunching, particularly when plantar
flexing the ankle.
Careful stretching of the soleus and
gastrocnemius when cooling down
reduces the likelihood of tendonitis.
Vulnerable muscles to a dancer
The groin (iliopsoas, rectus femoris,
adductors)
The hamstring group
The gastrocnemius
A thorough warm up will help reduce
muscle and tendon strains, as it will for
joint sprains. If you do injure yourself,
the following is a good guide!
How to cure an injury?
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