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Copy of The Healthy Performer
Transcript of Copy of The Healthy Performer
The Skeletal and Muscular Systems
The body is made up of bones, joints and muscles. There are 260 bones in the body. These are all attatched together by ligaments. They take up 20% of your body weight. The different types of bones are: long, short, flat, irregular and sesamoid (floating). Bones are rigid. They have a very complex structure making them very lightweight yet hard. Bones protect the main organs in the body from damage. For example the rib cage protects all the main organs in the body such as the heart and lungs. The spine protects the spinal nerve chord and the skull protects the brain. Blood cells are formed in bone marrow. Other functions of bones are movement, support and mineral storage. The strength of our bones help our muscles move as they are anchored together. Bones store fat and essential minerals needed. Healthy bones remodel themselves in response to mechanical demands of the body. Dancers bodies are constantly faced with new challenges, therefore their bodies are constantly changing. Bones lay new bone down where needed and reabsord bone where not needed. Many factors can affect the remodelling of bones such as race, age, hormones, gender and availability of calcium. It is important that a dancer stays healthy and strong as the movement required of a dancer is very un-natural. The pelvis, for example is constantly changing its alignment. In a contraction it tilts forwards whereas in an arabesque it tilts upwards. To avoid injury dancers must have a strong knowledge of where their neutral alignment is.
There are over 600 muscles in the body. Muscles are organs constructed of blood vessels, skeletal muscle tissue, tendons and nerves. There are two types of muscle: skeletal muscle and cardiac muscle. Skeletal muscles are voluntary muscles used to control all the physical movements we do every day. Ie. walking, talking. The function of the skeletal muscle is to contract moving the muscles closer to the bone generating control and movement. Opposing muscles work in the opposite way. Its important dancers opposing muscles are of equal strength to have the most effect. The stroger a muscle is, the stronger the joint is that its atattched to making it less prone to injury. Ways of strengthening muscles is through dance class and isotonic exercise. Repeated exercise in class improves muscle endurance giving the ability to perform for long periods of time. It also helps resist fatigue. The cardiac muscle is only found in the heart and it is and involuntary muscle, pumping blood around the body. Cardiac muscle stimulates itself to contract.
This injury is most likely to occur when forcing turn out, losing control when landing a jump or twisting knees during movement. It is the tearing of cushioning knee cartilage. Some dancers may be more prone to this who are competitive and under pressures from their teachers may be forcing their bodies without the graduated stretching and strengthening. Genetically a person could be born with tight hips causing their knees to twist when turning out. To treat the injury you must ice it straight away using the R.I.C.E method of treatment (rest, ice, compress, elevate) and make sure the knee is elevated above waist height. As you ease back into dancing make sure you wear a support on your knee to take some of the pressure away. A strong core is crucial for good knee health. It takes the burden off the knees in landings. To prevent further knee injuries core strengthening exercises are suggested. For example pilates is a good way of strengthening the core. When warming up before any exercise you must warm up all the joints.
65% of Injuries occur from overuse.
A very common injury in the studio is achilles tendonitis. This is the degenerating of tiny fibers in the muscle which then swell and thicken. It is an overuse injury caused by acute over training. Initially the dancer may have been under pressures such as stress or heavy work schedules causing them to not focus and warm up properly therefore the injury is already likely to happen. Dancers with less flexibility in the calf muscle are predisposed to this injury. On the other hand poor working conditions such as hard floor could also cause this injury. Achilles tendonitis is responsible for the thickening of the tendon, pain and stiffness and severe pain the day after exercising. Similarly to most injuries the immediate action is to rest, ice and take anti-inflammatory medication. Heating ad icing at one minute intervals will stimulate blood circulation. A number of exercises can be carried out to stretch and strengthen the muscle such as calf stretch and heel drops. The injury could have been prevented through wearing supportive footwear when not exercising as well as having the correct extrinsic factors ie. sprung floor. Basic thera-band resistance work can also help to strengthen the achilles.
Its very important that young dancers try and prevent injury as it can stunt growth and development of the body therefore to prevent injury you should be drinking at least 2 liters if water a day, warming up and cooling down before and after class, have a balanced diet and sufficient working conditions. ie. temperature, flooring etc. Dancers must have the knowledge of how to defrenciate aching pains from actual injury. Research shows that young people going through maturation are more prone to injury as their muscles tire faster. 90% of injuries occur when a dancer is fatigued. This is why an understanding of their bodies is important.
To create dance movement many muscles are used. A position frequently used in ballet, the arabesque uses many muscles to effectively create the correct shape. The abductors are situated on the lateral surface of the hip joint with the ilium and allow movement in the hip. In an arabesque they contract rotating the leg outwards allowing maximum turn out. The adductors work in opposition with the abductors and must be of equal strength to ensure one done not compensate for the other. The adductors are located on the medical surface of the hip with the ischium and pubic bone. They also allow movement in the hip. The muscle contratcs in an arabesque increasing the height of the leg. Working in conjunction with the adductors are the quadriceps. The quads are located on the front of the upper leg, made up of four seperate muscles. These are also connected to the ilium and femur. They allow extension of the knee and flexion of the hip. The quadriceps aids the lifting of the leg as well as many other muscles. The hamstrings are found on the rear surface of the upper leg, crossing the kneed and the hip, they produce movement at both joints and are connected to the ischium and femur. The hamstring allows flexion of the knee and hip extension. In the case of an arabesque the hip is extended backwards. The pelvic floor plays a huge part in all dance movement as its acts as your core stability. It is situated in the pubic bone. The pelvic floor stops you from losing your balance. Lastly the tibialis anterior is a long muscle on the front of the lower leg and helps stabalise the ankle. It is found on the tibia. In order to have a strong looking arabesque your ankle must be held and not wobbling. The tibialis anterior helps this.
This is an overuse injury most common to athletes such as ballet dancers and basketball players who run and jump on hard surfaces for long periods of time. Bones are constantly remodeling themselves and adapting to their environment. A stress fracture usually occurs when a dancer increases their training amount over a short period of time. The bone remodels itself, becoming stronger in the areas under more stress but if the bone can't cope with the new repetitive demands then the outcome is a stress fracture. A contributing factor of a stress factor is poor nutrition as this can cause the bones to be unhealthy. Dancers and athletes are very aware of their bodies therefore poor diet may be the result of bad psychological health. Appropriate treatment of a stress fracture would be to ice the injured area and keep it rested, avoiding the overuse activity and weight bearing. Supportive footwear is also beneficial. Exercise should be introduced back gradually. To prevent stress fractures you must maintain a healthy diet and vary the activity you do. For example alternate between running and swimming.
A blister is a bubble on the skin filled with serum. They are usually caused by burning or friction. Dancers are prone to blisters as they are common on hot, wet feet. They often occur in pointe work or floor work. Blisters must not be pierced. A blister should be covered with a foam ring and secured with hypal tape. To prevent blisters dancers should cover the areas on the foot with plasters or tape to minimalise rubbing. It is also said that rubbing alcohol on your feet can toughen the skin.
Flat bones: provide protection for the vital organs (skull) and act as anchor points for muscles such as the scapula.
Long bones: these provide strength and mobility.
Sesamoid: they are embedded in the tendons to increase joint movement.
Short bones can be found in the hands and feet.
There are three types of joints:
Fibrous (fixed joints)
Cartilaginous (slight movement)
Synovial (freely moving joint) ie. knee joint
Plane joints are found in the spine, Saddle joints are found in the hands, hinge joints are found in the knee and elipsoid joints are found in the neck. Joint movement is controlled by muscles.
The knowledge of the skeletal and muscular systems is very benifitial for a dancer. It helps them be more in tune with their bodies, understanding and being able to defrenciate pain and muscle soreness preventing injury. Understanding the anatomy of the all the muscles and bones improves overall performance of a dancer. Analysing the muscles used in each movement makes a dancer think about what goes into the movement. It encourages them to work to strengthen weak areas correctly and in a more scientific way with the knowledge that muscle strength improves joint strength. Understanding the causes of muscle fatigue will help dancers stop getting tired and improve their performance in class, knowing it builds stamina. Having the knowledge of what muscle flexibility can help do in dance pushes dancers to want to constantly be improving their flexibility and strength.
The Nervous System
The Respiratory System
The nervous system is a collection of cells that sepecialize in transmitting signals between different parts of the body. Signals are transmitted from the central nervous system from nerve cells and muscles fibres contracting. Muscles can change shape and the nervous system constantly adapts to the new muscle shapes. Motor skills are the skills we need to do everyday things like walking, running, speaking. Our fundamental motor skills develop as a child. We have a central and peripheral nervous system. It is important that we train our nervous system to reinforce pathways of the nerves. Movements come from the cerebral cortex part of the brain. It takes time for pathways to be established which is why new movements feel awkward. Training of these pathways improves neuromuscular coordination and the repetition of movement improves speed skills. Within dance, our motor skills help us have the ability to control physical extremities required such as pointing feet. It also helps our stability skills. For a dance movement to be executed with ease it has to be practiced and repeated until mastered.
This is the inability to carry out coordinated skills with normal accuracy. It can affect both gross and fine motor skills causing trouble with walking, running and other finer things like writing, word pronunciation and whistling. Dyspraxia is the delayed development of neurones (brain and nervous system). Dyspraxia causes someones motor neurones to not mature and develop as quickly.
The respiratory system is structured in two parts. The upper tracht and the lower tracht. The upper tracht consists of the mouth, pharynx and the trachea. The lower part is the lungs, brochiai tree and diaphragm. The main functions of the respiratory system are to ventilate the lungs, romove co2 from the lungs and release oxygen into the bloodstream. Breathing in dance is very important. Breathing correctly allows oxygen to the lungs and release energy. It gives a dancer endurance and the ability to perform for longer. Wheras if a dancer does not breather properly tension can build up making it harder to breathe causing the dancer to be more suspectable to tiredness. Many factors affect your breathing. Environmentaly heat and pollution can be detremental to ones breathing as well as smoking, colds, congestion and panik attacks. Smokers are putting carbon monoxide into their bodies making it harder to take oxygen and relase into the body causing them to be unable to perform for long periods of time and be more prone to injury and affect their overall health. Many dancers hold their breath when dancing due to nerves. Correct breathing improves a dancers performance and adds quality to it. Improvement in posture also improves breathing patterns.
The circulatory system is made up of the heart, blood vessels, blood cappililaries, arteries and veins. The main functions of the circulatory system is to pump blood around the body delivering oxygen and nutrients to all the organs then returning deoxygenated blood to the heart working in a double functioning way.
The veins have thin walls and larger internal lumen. They carry blood to the heart and contain valves to stop the blood flowing backwards.
Arteries carry blood from the heart to the organs. They have thick walls of muscle containing blood under high pressure.
Capillaries are only one cell thick and are found in the lungs and heart. Oxygen passes through the capillaries into the tissues and co2 is carried through into the blood.
The circulatory system is key in dance warm up. Fundamentaly in warm up we look to see a rise in heart rate; delivering blood glucose to the muscles giving energy, faster breathing; allowing more oxygen to be pumped around the body, rise in body temperature; capillaries dilate and you start to sweat and distribution of blood; blood is encouraged to areas like the muscles.
Breathing in performance in very important as it gives a dancer longevity. Breath is regulated by the nervous system in the lower brain as well as your heart rate. Nerves can kick in when about to perform which is why it is key that humans can control their breathing voluntarily via the motor cortex in the nervous system. The circulatory and resipratory systems both have the same goal which is to get oxygen into the body and co2 out. It is common for a dancer to be short of o2 when dancing as they do not breathe properly. The heart detects how much oxygen is in the blood. If their is not enough its send the deoxygenated blood back to the lungs to get more oxygen. This is very benefitial for a dancer as it encourages blood flow through the body keeping the body warm. This is why warm up is so important to ensure the heart is working at a fast rate before exercise.
If a dancer understands that breath can be controlled voluntarily it could be what makes their dancing better by encouraging them to stay calm and find a breathing pattern that works for them. The importance of warm is not recognised enough by dancer which is why injury is so common. Dances should understand that Just an increase in heart rate could affect their body beneficially in so many ways. For example its increases blood flow and body temperature and passes more oxygen around the body.
Dance Injury can be emotionally very draining. It causes a lot of pain and depression, especially with the more serious injuries because ultimately your taking away that dancers life which is why many proffesional dancers dance on injury. People react in different ways be it physical, behavioral, socially or emotionally. Initially one feels shocked and scared. As the physio progresses dancers become more encouraged.
Dance Injury - Psychological Effects