Suche

Menu

Suche Trainingspläne

Letzte Kommentare

  • Tanja Heinz zweifache Deutsche Mastersmeisterin!!!
    Ulrich Ringleb 11.09.2021 14:13
    Großartiger Erfolg! Glückwunsch allen Beteiligten ... :lol:

    Weiterlesen...

×

Warnung

JUser: :_load: Fehler beim Laden des Benutzers mit der ID: 62

Schwimm-Ratgeber

Zugtechnik

Details
Kategorie: Technik
Zugriffe: 5977
Print Friendly, PDF & Email

By Bernie Wakefiel7d

Every now and again, as coaches, we are requested to provide accountability to parents. Some years back I was approached by a swim dad, who demanded an answer to, what seemed, at the time, to be a reasonable question. His query was "Why do swim coaches insist on teaching a backstroke stroke with the arm as a bent lever when science declares with some authority that the straight lever is a far more effective tool?"

I began to explain in simple terms then suddenly realised I was committing myself to a number of complex issues connected to the answer to which I could not easily give a precise response. Incoherent rambling comes to mind. This parent had a background of civil engineering, which meant he had a better than average concept of mechanics, either in building bridges or understanding biomechanics.

Think now before you jump to a quick solution to his question, for even profound thought could produce a hazardous answer. The parent was evidently directing his concern to a proclamation of Archimedes, a gentleman renowned for raucous outbursts. "Eureka! I have found it!" was one rather obscure declaration he expressed loudly after leaping into a bathtub – and he wasn’t referring to the soap!

But his most notable, probably his zaniest and the statement that the parent referred to was "Give me a lever long enough and a prop strong enough and I will move the World!" Which was rather difficult to prove or disprove as a lever that long would be hard to find on this planet – and of course the lever would still need something solid and unmoving to anchor it. Mars perhaps?

Giving his observation some rational thought on an earth-bound basis, he was dead set right, as he was with all his statements, pithy or not; it is the best way of moving anything by force with unlimited resources of man-power available. The ancient Egyptians were aware of this simple but clever method of moving massive items. The pyramids were constructed in this manner and the same formula was used to move those huge hand-hewn blocks of sandstone over incredible distances to the building site. Whoever built Stonehenge three or four thousand years ago employed the same process. So why don’t we apply the same techniques to make our swimmers faster?

I guess the easy answer to that is, as levers, our arms are neither long enough nor strong enough to supply the dynamic energy necessary to move the body fast enough. But that simple response just poses more teasing questions, the major one being that we are not referring to an earth-bound exercise but one which is confined to water.

Perhaps though, before dealing with fluid dynamics, we should delve a little into the world of mechanics and investigate the function of these miraculous levers.

Basic engineering recognises three types of simple machines called levers. The First Class lever (and let’s begin by stating that all these levers are straight ones) has the load at one end and the applying force the other end. Somewhere in between is the point of leverage. This is known as the fulcrum. The longer the lever is, with the load nearest to the fulcrum point, the less effort is required to shift that load.

With the fulcrum point in the centre of the lever, the equal balance of load and force will produce a seesaw effect. But here lies the rub; that anchor point (fulcrum) must be fixed and unmoving at the moment leverage force is applied so as to obtain an optimal result. Which creates our first and probably the most dominant problem when this exercise becomes a human one and is transposed to water.

A Second Class lever can be likened to a wheelbarrow where the load lies between the fulcrum and the lifting force. It is still an effective device for shifting loads and in swimming, with the fulcrum constantly moving its position, this exercise in leverage will apply to at least some part of the arm cycle.

The Third Class lever has the load at one end and the fulcrum at the opposite end so the load being lifted requires far more effort than the other two types of lever movements. Like being in a supine position on the gym floor and lifting weights (pull-overs) with elbows now the fulcrum, resting on the floor. This motion will also be applicable at some particular time during the movement of all swim strokes.

So, it should be clearly seen that, for best performance, these fulcrum points on any of the classes of leverage used during stroking must be solid and motionless. An exercise, because of the lack of density of water, that becomes most difficult without highly effective stroke control. Any movement at that point of prop reduces both the distance and the velocity the load has to be shifted quite significantly. Remember this, for it is most important when relating these activities to the momentum of swimming.

Levers are used to multiply force.

FLUID DYNAMICS

Water viscosity is of course the medium which concerns us when swimming either fast or slow. Cecil Colwin illustrated in one of his lucid articles, "We don’t swim in air", the many problems associated with swimming, quoting another branch of science, Fluid Dynamics, as his source of information and hereby hangs a sad tale. Here we are trying to move the body through the water by using this same liquid as the support or fulcrum point where a lack of real solidity necessarily impairs forward progress. The swimmer, using the hands for propulsion by seeking a strong point of purchase where the arms can be applied as capable levers, cannot find water concentrated enough to completely stop the hands and maximally apply that full leverage. The simple reasoning behind the failure of the swimmer to apply supreme pressure is the fact that the fulcrum point moves steadily throughout the movement of the levers (arms) in water.

Because of this lack of stability in the catch position and the perceptible shifting of the fulcrum during the stroke as the arms (levers) change direction seeking a substantial plane, the levers could probably diverge from First Class to Third class status repeatedly. Because of this problem, the stroke action to maintain velocity requires more than the function of simple force. It needs a highly trained swimmer using a muscle memory technique to carry out the task without conscious thought. That situation would certainly change from swimmer to swimmer depending on the effective use of available power and state of trainedness

I t may also indicate that in certain circumstances the straight lever may act in a more positive fashion that a bent one – if that is possible.

Contributing to the retardation of the swimmer’s progress and the difficulty in obtaining an effective grip or ‘feel’ as it is often referred to, is the constant motion of the water they are moving in. Possibly Breaststroke, because of its powerful leverage and shorter application of stroke in producing propulsion in comparison to the other three, may be the only stroke or kick which can provide the ideal anchoring point. More on that issue later.

I would suggest that, no matter how effective the swimmer is in applying force or how good is the technique in any stroke, we are mere tyros in mastering this desired perfection of purchase. The hands of even the most talented of swimmers (or feet of breaststroke kickers) move some distance backward through the water. Perhaps if we were as efficient as some marine creatures we could come close. Maybe sometime in the future.

Other stumbling blocks in the path of clean movement through water are Drag coefficients. I’m not going into that ... more accomplished people than I have ably demonstrated those detaining components. But that problem is ‘merely’ a lack of streamlining of the human body, both in shape and action. Now that we are well aware of these demeanours that restrain our swimmers, we will do our outmost to teach perfect technique. Won’t we?

HUMAN WEAKNESSES

A further dilemma can be human frailty. If the influencing force applying the lever isn’t powerful enough to grasp and hold the point of prop (read catch) then the movement of the body through the water will be limited in speed. On the other hand, supposing the swimmer possessed perfect technique – whatever that is – and WAS strong enough to hold that vital catch position (read prop) then the speed of the body will be increased to optimal performance. That is, all other things being equal.

What other things? I mean apart from the streamlining and strength factors? Well, aside from these two vital physical ingredients, human beings are somewhat fragile in other areas. The inability to control the mind to direct the body to a perfect physical action is a universal problem among people undergoing stressful conditions. One of those natural responses is the creative flow of positivity often being over-whelmed by its treacherous companion, negativity. This leads directly to inadequate self-command in a race or similar circumstance. So, without a controllable discipline in this area of concern, we may be doomed to a miserable 7k per hour compared with some of the greyhounds of the sea who are capable of speeds rocketing up to 70K per hour.

If you don’t believe, you will never achieve.

THE STROKE LEVER OF BACKSTROKE

That still hasn’t solved the question of straight versus bent lever action, although we may be approaching a compromising explanation to the enigma – or are we? Perhaps in the practical application of machinery, the civil engineer had it right with his statement that the straight lever was superior but the probability is that we do not yet possess the competence to swim in that ideal fashion. And that leads on to a self-deprecating tale of yesteryear.

I had this young lady, perhaps twelve years of age, come to me for training having shown some talent in her local school pool. Her best stroke was backstroke and she was certainly a slick and quick mover in this stroke. But she had a major fault. Well, according to the text book on attaining technical perfection, her stroke mechanism was more than suspect. She was guilty on all counts of swimming with a straight arm action! Her fingers actually scraped the bottom of a 25m school pool which in this State is one metre deep at the shallow end. Which meant that not only did she own a remarkable innate strength to attain the speed she had but she also had an excellent shoulder flexibility to reach down that far.

Being an ever clever and thoughtful bloke, I promptly began to change her to conventional stroking. This process took me at least two years of frustration, of conversations conducted a high pitch level and lots of grinding of teeth in my sleep. However, I succeeded, in that two-year period to send her fastest time to the recycle bin. And come up with a new time of, wait for it, over 50 metres, two seconds slower! Success, on this occasion, was restricted to a doubtful stroke conversion – definitely not a faster speed.

What did I learn from that episode of mind-numbing futility? One, in the first instance, that she was strong enough to use the straight arm lever principle and secondly, I actually hindered her progress to a promising career by not allowing her to swim in her most natural configuration. This incident happened a long time ago and I am not using this as an excuse for ignorance, the situation of change should not have continued after persistent failure. It did however, plant the seed of doubt in my mind about accepting traditional rules and activated my mind into questioning everything I ever read on swimming from that moment forward.

Curious how one thing leads to another. I began this article with very strong thoughts on the practicality of using the straight lever in swimming but deeper thoughts produce opposite images that only cloud and confuse those issues. I just thought of another analogy, which may negate the straight arm version of swimming and of necessity, must enter this debate which was rapidly becoming one-sided. But always arbitrary!

THE CASE FOR THE BENT LEVER

Here is an actual and personal encounter with the subject in discussion. I consider myself a very lucky person to be able to study that great Australian distance swimmer, Steven Holland from a young boy until his prime, not only competing but also training. For those of you who are not familiar with Steven’s form, this is how he stroked.

He was not a big man in the sense of broadness or height. In fact, at the apex of his career he would have to be on tippy-toes to reach six foot with a slender body to match. His kick was almost non-existent, being of a one and a half beat variety .One leg dolphined and the other trailed in a sort of half dolphin. His stroke was a fast turnover with elbows bent at close to 90 degrees. To those coaches who preach and teach slow-rating to their swimmers, he presented a nightmare model to copy. Despite this, or maybe, because of this, he slipped through the water almost effortlessly and his fastest time for the 1500m of 15.04 in 1976 compares most favourably with today’s champions. In the opinion of a lot of good coaches of that era, Steven never attained his full potential, not because of his stroking but because of over-officious swimming authorities.

However, I have to point out that over shorter distances of 100 to 200, Steve was not so flash in comparison with the 1500m men of today, Perkins and Hackett, even though his 400m was competitive. That lack of real sprinting power was undoubtedly due to his unusual stroke and kick – and his particular body structure.

The reason I used this analogy is to compare impartially, this type of stroking with results from using the much longer lever. At least in distance swimming it can be seen to be a favourable comparison. Perhaps too in the shorter and faster distances it could be pertinent to the rapidly rating swimmer with a slower two-beat kick. We have seen many instances in the recent past of this type of swimmer, sprinter or distance, male or female, two or six-beat, enjoy success at World class level, We cannot categorically rule it out.

THE STROKE LEVER OF BACKSTROKE

This tale concerns a young Hungarian girl who trained in a top National squad in Europe. Because of her age - twelve, and the fact that she was so slim and tiny, the coach, Lazlo Kiss, slotted her into that narrow space that often occurs between outer lane markers and the side of the pool. This area would be no more than two feet wide – 60 centimetres.

Backstroke happened to be her best stroke but because of this limited space to swim in, she was compelled to use only a slightly bent arm pull and push exercise with the arms reaching deep under her body; a movement closely related to freestyle stroke technique. At her deep grasping point, she rotated her hands and forearm. To achieve this complete motion her shoulders needed to roll quite considerably. To keep her head absolutely still during this cycle of arms, she swam with an empty tin placed on her forehead. There was probably some elbow bend during the stroke but circumstances did not allow anything different than almost vertical lever action.

Would it surprise you to know that she went on to become a very good exponent of this stroke? Good is hardly the right word; she became the finest female backstroker of all time and her World record in the 200m is regarded by the best critics to be at least as good as MaryT Meagher’s 200 Fly and Janet Evan’s 400 Freestyle records. Her name is Krisztina Egerszegi.

(Note: I cannot help myself, stepping up on my small soapbox once again. I have to tell you also that she did not commence specialist training for this stroke until eighteen years of age. Neither did she have a background of big mileage in her tender years. (Reminds me of a certain Australian girl.)

So maybe these two tales will create a touch of confusion or at least an element of doubt into the dilemma of teaching either bent or straight actions in stroke mechanics – in backstroke anyway.

THE STROKE LEVER OF FREESTYLE

Perhaps this would be a good time to introduce the conventional S-shaped sweeping action of freestyle using the accepted high elbow, pull and push stroke. Consider for a moment this classical movement of the hands taking up the catch, ever seeking the feel of water solidity. Front on viewing would disclose a simple model of efficiency as the hands, supported by the anchorage point of the shoulders – attached to the load (the body) being shifted – sweep downwards and slightly inwards, slowing ever gradually until that moment of firm catch. At this point, the power and the propping point is transferred from the shoulders through the elbows to the hand, propelling the body forward.

The stronger the swimmer, the more leverage can be applied; the longer the lever, the more power can be utilised in the catch position if the stroke is efficient enough to carry out the task. Speed increases. A bit like running really with the advancing leg making contact and taking a grip on the ground and pulling and then pushing the body forward. The ground being the unmoving fulcrum of the thrusting legs.

But swimming isn’t as simplistic as that and other factors are involved, including the lack of a fixed anchoring area as I pointed out earlier. However, the concept still applies to some extent, at least for the purpose of understanding biomechanical progression in the water.

One could argue at this time that if the swimmer’s strength was potent enough then there is nothing wrong with a straight arm pull. Certainly the stroke rate would decrease and isn’t that what we are trying to teach? Complete management of all the maximum power the body can supply? Is here a problem here with symmetry, rhythm, streamlining or balance? I doubt it.

Even when we continue the length of the stroke to its conclusion to the hip or past, it is still a shifting of the load we are seeking – which could be expressed as the power of propulsion.

Unfortunately science has not yet devised an accurate formula for velocity in the water due to the many variables which confront us in our endless quest for utmost speed.

.

Now let’s view the action of the freestyle stroke from the same angle but from a different perspective in a hypothetical but I hope, creative sense. Let us imagine first that we are using a crowbar to lever out a stubborn rock from the ground. After exhausting all means to extract the fixed item in question using the short but STRAIGHT crowbar, we resort to the longer lever principle by adding a long section of tubing to the bar and again apply the pressure. Lo! The rock emerges easily from its position in the ground.

Long Lever Rules! Okay? All right, now we take the same crowbar, heat it in the centre of its length and bend it to the same angle that we expect swimmers to bend their arms during the freestyle pull.

Now let’s try to extract a similar rock from the same position even using the extra length of pipe. Do you know what will happen when we exert the same pressure as we did with the straight bar – but with the angle adjusted to the same as the swimmer employs? Yep, the rock may emerge but the chances are the lever will slip sideways because the weakest section is now at the point where we bent the bar. In the same manner as a swimmer’s elbows drop when they can no longer exert the same pressure during an intensive swim.

Score one for the straight arm! Mind you, if we could keep the crowbar bend angle facing either up or down and not sideways, then there will be no loss or gain of power influence. But of course, elbows don’t bend enough in the direction that we need for full power application so there is little point in debating that issue. And, let’s not forget there is a vast difference between steel and flesh so there is another flaw in that argument. But the thought, like a pesky fly, still persists.

In the beginning of this article, I briefly mentioned the power of breaststroke and the characteristics of its short pulling and kicking action. In my early days of coaching, during winter months I was forced through insufficient heated water space into experimenting with tethered swimming. Among the welter of white water caused by too many swimmers and too little space, emerged a curious situation.

I could not help noticing that breaststrokers stretched the elastic tether further than swimmers doing other strokes. Puzzled by why this occurred I attached a simple tensiometer device to the tether of a breaststroker and measured the force output in pounds per square inch. It was not too surprising to observe that they did exert a far more powerful pull with their arms (plus legs) – about double the output of all strokes in their entirety! Measuring pull only as against all other armstrokes only, the output reading was still doubled.

If we then accept the premise that the most forceful part of the armstroke is the beginning of the insweep then we must examine the subsequent revelation. With full arm extension in the wide outsweep of modern breaststroke now a fashionable exercise, (among the strong swimmers at least) has it become an outward and lateral version of the long lever principle?

THE BUTTERFLY STROKE LEVER

This quaint mixture of Breaststroke and Freestyle stroke (in that order of arm movement) produces a powerful, sweeping stroke action which is also bound to the long lever principle. The early catch, outward press and rotation of forearm is strongly related to the lateral lever of breaststroke at the beginning of the insweep, although the timing of this action begins much earlier in the butterfly operation. The longitudinal pull and push from there on is similar to freestyle and in doing so, bears identical characteristics of this stroke depending on the supply of accessible power. There seems to be little reason not to pursue identical leverage of straight arms if the machine (body) had the capacity to produce and maintain that activity.

FREESTYLE AGAIN

One more true story and no more, I promise you. Dawn Fraser. Our greatest ever sprinter in terms of Olympic results and World records. Dawn’s freestyle action was smooth and graceful, no doubt honed that way by her great coach Harry Gallagher. It may interest you to know that she swept her arms so far across the centre line that her hands lined up with her opposite hip. Did that hinder her? Would she have swum faster by sweeping down the centre line? Taking it a step further, would her progress have been more rapid had she pulled with a deep and long straight lever? There has to be some validity about any of those theories but it obviously suited her physical structure to stroke that-a-way. Perhaps the Old Fox himself could enlighten us on that score?

The past thinking on the use of such a wide pull was that it tended to torque the body into a yawing situation and the swimmer’s progress allegedly became similar to that of a snake’s passage through the water. Dawn certainly did not exhibit any such tendencies. Was that because she was strong enough in the shoulders and torso to employ the long lever in a different perspective to what is considered normal? Like a balanced shoulder roll cancelling out the tendency to torque?

I know it is tedious relating past and present champions. Will Shakespeare called it odious and comparisons are a bit offensive in a lot of ways. Just disregarding the great debate for a moment and digressing, Dawn’s times of the fifties are way outside the nineties but had she had the opportunity to train with scientific help, heated pools, speed assisted costumes and a controlled diet, how much faster would she have gone?

Conclusions are now in order. Just what has this article proved? Nothing really that you could say positively, is the absolute certain way of individual stroking. Did I strike a responsive note there, individual? For this is the sweet chord of awareness ... the realisation that every person has a structure that differs to the norm (what is normal?) and requires a distinct and specific way of extracting the same firepower.

The notion however, that the theory of long straight levers being compatible to strong swimmers still lingers.

STROKE MECHANICS TWO

FAULTS AND FLAWS

At a pool I once coached at, the lessee asked me to conduct a stroke seminar over a Christmas period. I began the first session describing the pleasurable movement through the water regardless of what stroke they were doing. The spiritual aspect of swimming ... a state of being a molecular element of the water, as nature intended.

Not being a very imaginative chappie, he did his Nanna because he wasn’t expecting a philosophical session but one that dealt with only how good the swimmer looked in the water. "The Pursuit of Excellence" he called it. "A Cosmetic Facade" was my thought. He had no idea that I was attempting to find the natural and therefore, the best technique for those pupil swimmers. Constructing their stroke in the same manner of any competent coach of any sport. With feeling.

BACK TO BASICS

Even with the very best of swimmers, the learning concepts can be difficult to teach especially when you are attempting to clone a model you have designed in your head. Sometimes we have to admit defeat. For one reason or another it can be impossible to modify a stroke so you have to make do with what you are left with – which is generally the swimmer’s best stroke anyway, the one that they have had the most success with. Often even that stroke needs attention and this is where major issues arrive and you may have to study the stroke patterns in relation to the swimmers structure, strengths and weaknesses and re-design the whole blueprint of stroke.

Not only re-plan it, but it may be beneficial to go back to taws and start all over again. Somewhere, sometime in the swimmer’s background, a fault occurred that had a major impact on the biomechanical patterns and these are the stumbling blocks that have to be removed forever. A few laps of the pool doing an altered part-stroke is not the answer for those swimmers, who will inevitably return to their former defect as soon as they tire.

The best method is to completely return to basics. Pretend, if you like, that this is a development class and you are teaching a new stroke. Make the swimmer aware of this situation to get into the mood of the scenario. Twenty minutes of teaching basics will return astounding results. All the old neurological patterns have to be removed and replaced with new ones. It is only a matter of mental acceptance by the swimmer before the new stroke emerges. The more enthusiastic the swimmer, the faster the acceptance. May I also suggest that much of this development work be conducted at high velocity over short distances so the body can completely memorise all those important factors that control speed in the water.

Sometimes, when doing this sort of correction, the reason for the prime fault will become apparent and it may be possible to treat or alter this flaw in those early days of the new stroke development. But try, at all times, for the natural function and endeavour to model the stroke to the swimmer’s strengths.

Summing up; I don’t think I have completely solved any real problems, maybe chucked in a few more ideas to play around with, but I believe there is a lesson there that will stick if you accept it. The way to a perfect technique is paved with difficulty; for some people it may never happen for any number of reasons and you may have to settle for something that suits the structure or even character of the swimmer. But before you make an absolute decision to alter a stroke in any way, think again, are you doing it for cosmetic value – just a pretty face to admire? Or are you certain the change will bring more speed? You must be sincere in your beliefs.

Neuere Artikel

Weitere Artikel

Beliebte Artikel

Print Friendly, PDF & Email

Kommentar schreiben

Sicherheitscode
Aktualisieren

Registriere dich für unseren Newsletter - alle drei Tage neu!
captcha 
Copyright © 2024 Gießener SV Schwimmen. Alle Rechte vorbehalten.
Joomla! ist freie, unter der GNU/GPL-Lizenz veröffentlichte Software.

Joomla!-Debug-Konsole

Sitzung

Profil zum Laufzeitverhalten

Speichernutzung

Datenbankabfragen