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Rabu, 24 Maret 2010

Biomechanic of Swimming

Over the last 10 years, our understanding of the biomechanics of swimming has been revolutionised by the development of particle imaging velocimetry (PIV), which has revealed details of the complex fluid flow patterns around fish and in their wake. Eric Tytell, Emily Standen and George Lauder briefly review the current understanding of the fluid dynamics associated with fish swimming (p. 187), but also sound a note of caution. Pointing out the consistency found in the wakes of fish ranging from eels to mackerel, they warn that the simplified two dimensional PIV view could have obscured more complex fluid flows occurring in three dimensions. Expanding PIV techniques into the third dimension, the team discuss their work on the bluegill sunfish, brook trout and yellow perch, analysing the fishes' dorsal, anal and median fin motions during manoeuvres and free swimming. Identifying complex interactions between flow from different fins, the team say that `these data demonstrate that, while fish do move primarily in the horizontal plane, neither their bodies nor their motions can be accurately simplified in a two-dimensional representation'.

Scaling down from adult to larval fish, Ulrike Müller, Jos van den Boogaart and van Leeuwen point out that the sticky environment experienced by miniature swimmers is very different from the more fluid environment experienced by their adult counterparts (p. 196). Analysing fluid flow patterns as larval fish accelerated from stationary, swam steadily and came to a halt, the team found that tiny larval zebrafish swim with a wide body amplitude. They also found that the larvae are hugged by a relatively thick boundary layer, unlike the adult's relatively thin layer, and that the wake dies off quickly. When setting off, the larvae bend themselves into a C shape followed by a propulsive stroke, and when stopping they gradually reduce their tail beat frequency and amplitude.

While much has been learned from in vivo studies of swimmers, studies of robotic fins and wings can also teach us a great deal about the hydrodynamics of swimming. With the aim of developing robotic submarine vehicles, Promode Bandyopadhyay, David Beal and Alberico Menozzi, working at the Naval Undersea Warfare Center in Rhode Island, USA, have designed and built a robotic fin, loosely based on a penguin fin, which they can control while directly recording forces exerted on the moving limb (p. 206). Based on measurements from the moving fin, the team have developed a model that allows them to calculate the lift and drag exerted on a stiff, penguin-like fin, and to calculate optimised oscillation parameters for the fin during swimming. Surprisingly, the rigid fin's wake was remarkably similar to an eel's, shedding vortex rings alternately to the left and right (although the robotic fin's vortices die off more rapidly than the eel's). The team have also compared the performance of the rigid penguin-like fin with the sunfish's flexible pectoral fin and concluded that although the sunfish's fin confers greater hydrodynamic variation, penguin fin analogues may be better suited to propel biorobotic vehicles.
for detail you can look at here




http://www.ziddu.com/download/9148130/biomecanicsofswimming.pdf.html


Minggu, 21 Maret 2010

Swimming for Baby

THE BENEFITS OF BABY SWIMMING

EMOTIONAL BENEFITS
Swimming allows babies to move independently much sooner than they are able to on dry land.
Imagine the boost of confidence and self-esteem that movement through the water brings your child as she explores her new, watery environment. Every time you catch your child after a jump or a short swim, she learns trust.When you praise her for each small achievement on the way to mastering a skill, you build her self-esteem. Babies’ faces glow after they successfully accomplish a task—they look for approval and validation, and parental acknowledgement of their efforts fosters their personal self-acceptance and pride. Swimming can be very empowering for babies, since it offers them a new sense of freedom

Parent-child bonding Where else but in the water can you commune faceto-face, skin-to-skin with your baby for extended periods of time in a warm and inviting natural element? Teaching your baby to swim increases your bond with her as you play together and move in unison, and as
you exercise patience, encouragement, and kindness toward her.You will learn about her rowing personality, sense of humor, and how she approaches new situations. As you teach her, you will become aware of her learning style and her changing needs and abilities. This knowledge will not only aid successful baby swimming but will also help you establish positive parenting methods that you can use outside the pool.

A study conducted by Professor Liselott Diem from 1974 to 1976 at the German Sports College in Cologne, Germany, found that children who learned to swim at an early age demonstrated advanced development in:
motor skills
reaction time (reflexes)
power of concentration (focus)
intelligence
social behavior
social interaction
self-confidence
independence
coping with new and unfamiliar situations.
Overall, children were found to be more well-adjusted than their peers who had not participated in early swimming programs, and the increase in both self-esteem and independence due to baby swimming were cited as contributory factors.The study also concluded that children who swam from an early age benefitted from positive interaction and bonding with their parent

SOCIAL BENEFITS
If you can gather a group of like-minded parents and teach your children together, they will reap the social benefits—they learn from their peers by observing and mimicking them, and also enjoy their company. Children begin to look forward to interacting with each other, learning to take turns, to share, and to try new skills.

PHYSICAL BENEFITS
All the fitness benefits that swimming brings adults —an increase in strength, muscle tone, endurance, and lung capacity—are also enjoyed by children. For young babies, movement through the water liberates them from a comparatively static life, and allows them to exercise muscles that would otherwise not yet be used. For older babies, swimming is the natural implement to their growing repertoire of land-based skills. Because both sides of the body are involved, and therefore both lobes of the brain, swimming increases coordination, motor development, and balance. Parents also see better sleep patterns after swimming

PERSONAL SAFETY
With time, practice, and developmental capability, children can acquire the necessary swimming safety skills to aid them in the event of a water emergency. A calm child who feels at home in the water and who has regularly practiced safety skills with her parent will not panic, but will rather proactively implement the techniques she has learned. Note, however, that no child should ever be considered “drownproof,” and you should always be vigilant when your child is in the water.

POSITIVE TEACHING METHODS
Being a proactive, positive parent directly helps to nurture a well-adjusted, happy child. When teaching your baby at such a young age, you have the opportunity to build trust, share joy, communicate by touch and words, and bond with your child as he experiences new and varied stimuli. The impact you have on your child at this young age cannot be overestimated, and baby swimming is a unique opportunity to develop and put good teaching practices into action.

THE CHILD-CENTERED APPROACH
We live in an era that has benefitted from research into the capabilities of babies. No longer seen simply as little lumps, babies regularly astound scientists with their innate abilities.We now know how even a very young baby can discern faces, language, and emotion, and how activities and experiences affect his mental development. Although babies develop many skills from an early
age, parents should not attempt to create a “super baby.” Children should not be pressured or pushed to perform, but guided to develop their skills at a rate they are comfortable with.

PROGRESS AT YOUR CHILD’S PACE

Just as children learn to walk, talk, and read at different ages, they also learn to swim at different rates. As a parent, it is critical that you do not place any accelerated expectations ahead of your child’s actual readiness to learn a skill. All children learn to kick when they swim—but some do it on the first day, while others do it only after a great deal of time, motivation, and practice. Kicking on the first day doesn’t make one child better, smarter, or stronger than another child who learns later—it simply means they are different and unique individuals.


Don’t worry about how quickly your child learns a new technique—just focus on helping him acquire a skill a little bit at a time. Make the most of the process and the time you are spending together doing an activity you both enjoy, and remember the most important thing is to make your lessons fun and playful.

Comfort in the pool
Both children and parents bring with them a host of previous water experiences—some positive and some negative. Some babies have been in the bath or shower with water pouring over their face from just a few days old, others have seen their older brother or sister swim underwater, and still others are fearful of the water because of a water scare or a previous bad experience
with an aggressive swimming program. Some children are shy and want to assess a new situation from a distance; others show an inherent aversion to having water on their faces, but some will bolt immediately into a new environment without a care. Remember also, if you are the gregarious parent of a reserved and cautious child, you will need to respect the fact that you have your own individual differences, and learn from your child what makes him secure,
comfortable, and happy in the pool.

THE IMPORTANCE OF BODY LANGUAGE
Even before your baby can speak, he is a very capable interpreter of your body language, and
will pick up on the slightest nuances.Your facial expressions, muscle tension, tone of voice, and
reactions will all convey clues to your child about his environment and how he should act. It is
therefore vital that you are relaxed and confident with him in the water, as he will pick up on your cues, whether positive or negative.
A relaxed, gentle touch and upbeat, playful, or calm tone conveys a sense of ease to your child.
Use positive signals such as smiles, hugs, highfives, applause, laughter, or a kiss to reassure your child and reinforce a positive atmosphere.
Don’t send mixed signals—for example, don’t force your child to carry out a maneuver and then give him a hug or a kiss. Use encouragement rather than coercion

You should carefully watch and interpret your child’s body language—especially if he is too
young to speak.This will help you assess his comfort level and whether he is happy with the
skills or games that you are practicing.
A relaxed, happy, smiling child is enjoying the experience. Note that his muscles will feel soft, not tight or tense.
If your child is clinging to you, it means that he is not ready and needs more time to adjust to the new situation. Don’t rush him or pull him away from you—give him the security he is seeking.
Crying is your baby’s way of telling you that something is wrong and signals a need to stop
what you are doing. Redirect your child’s attention with a toy or by playing a different game, and
assess what caused the crying.

Kamis, 04 Maret 2010

How to Take breath

Between four existing swimming styles (breast-stroke, free-style, butterfly stroke, and back style), difficultest manner breathe it free-style. in breast-stroke and butterfly stroke, breathe can be done easily caused by moment where does our head entire present on water level. Take breathe also not difficult because head and our body looks freely up at sky. as to in free-style, our head may not thoroughly bop up from water level. this make to breathe in free-style difficultes.

But if usually, there will be no again difficult matter. take (to sip) breath in our free-style does since 2/3 our hand paddling, and we terminate in moment our hand returns to enter to into water. we take example takes breath to left side. at the (time) of our left hand paddling is in a line with breast, will emerge style will lift in our body left side. Finally, body even also sloping will look to left side. at the (time) of that's we begin to take breath and our body slope by itself will help our face to be able to bop up water level easily and natural.

At the (time) of your face returns sunk into water, release air calmly from your nose. this will evoke secretory water bubbles from your nose.

then when do we take breath? for long distance swimming about 1500 meters, several great swimmers likes grant hacket take breath every two paddling once. this mean only intermittent one paddling, and hence breathe it even also only to one side: to left or to right.

But there also several swimmers that take breath every three paddlings once. This will mean breath taking will be done by turns to left and to right. manner breathes to like known as bilateral breathing. Then which better between take breath to one side or take second breath side according to by turns? the answer, likes you. Do that follow you more relax, relax, pleasant and suited for you, so above all, you felt pleasant when breathe.

Still, many swimmers sprint free-style (50 meters or 100 meter)s that try maximum may be to hold back their breath during race. they only take when really need it breath. The mentioned is being being done so that is not happening speed reduction usually is happen when a free-style swimmer is taking breath. To detect gesticulating in free-style swimming, click here. to detect technique swims free-style perfecter, click here. and to detect manner swims efficient free-style