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Evaluation of Swimming Technique
by Rein Haljand Rate this article:
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Methods of Evaluation for Competition Analysis and Technique in Swimming
Experience during a long period in swimming has shown me that Competition Analysis is very useful in preparation of high level swimming. Swimming performance consists of
START
TURNS
SWIMMING
FINISHING
DIFFERENT MANNER OF STYLES (stroke frequency, stroke length)
DIFFERENT TACTIC DURING THE RACE
We need to save, how the swimmers made their result in the event. How good was start, turn; what kind of stroke frequency was used in the beginning and in the end of the distance; how good was their finishing technique?
Why do we need that? Because we teach them to make good starts and turns, to swim with optimum stroke frequency and stroke length. We train not to begin too fast to win at finish. When the swimmer returns from a competition to begin preparing for the next, he needs to analyse what were his weak points and how the winner won? According to this the swimmer has to make corrections in his training plan.
Competition Analysis Parameters
START
time of 15 m from signal in sec
speed of 15 m from signal in m/sec
Timing 15 m from the start in competition indicate effect of Your start. During training You can also make starts with time control of 15m and compare with starts in competitions. It's important to know the world's best start times and start speeds. It is useful to compare the start speed with the speed of turns or swimming. Relay start speed must be usually better than at an individual race.
TURNS
15 m (7.5 + 7.5)
time from head in sec
speed of each turn in m/sec
mean speed of all Your turns in m/sec
In 50m pools it is normally 7.5 m, when swimmers begin to prepare for a turn (to find 5m flags and prepare roll for backstroke; to correct the stroke length for touching the wall) and also it is 7.5 m from the wall, when the swimmer finishes his turning actions, and continues to swim normally (in freestyle and breast, and longer now in back and fly). Timing turns is useful for comparing swimmer's first and other turns, comparing turns during competition and training exercises. Turn speeds make the comparing of swimming speed and turn speed possible and as a rule, turn speed must be better then swimming speed, to indicate turn's effect. Mean speed of all turns is for comparison with mean pure swimming speed especially for 400, 800, 1500 freestyle races.
FINISH
last 5 m
time from head to touching the wall
speed in m/sec
When we want to know how successful the technique of finish touch was, then the last 5 m are enough. There are 2 last strokes. A normal stroke length is approximately 2 meters and finishing time, measured from the head 5m before the wall, until touching the wall indicate how good the finishing was. For better comparison of the swimming speed in the last lap - before finishing - and the speed during the last 2 strokes, it is good to have the latter speed in m/sec. Finishing speed during the last 5 m is measured by dividing 4,5m into time from head to hand touch (the length between swimmer's head and fully stretched arm is approximately 0,5m). If the touch is successful, the speed must be higher than the swimming speed during the last lap.
SWIMMING
pure swimming speed in m/sec for each lap
real 25m, 75m times
average swimming speed in m/sec
Swimming speed during laps is measured after the start and before the first turn; between turns; after the last turn and before finishing. We call it the pure swimming speed, because there are no influences of start turn or finish actions. For long course races it is important to compare swimming speeds to know the fluctuation of the pure swimming speed during laps. Pure swimming speeds in m/sec during a competition are important values to know for planning the level of intensity for aerobic and anaerobic work, using lactate test methods for training.
DIFFERENT MANNER OF STYLES
stroke frequency (cycle/min)
stroke length (m)
These are two important stroke technique parameters, and useful to compare with swimming speeds during the race. They are very individual, but the difference between them in the beginning and in the end of distance will show the swimmers technical and tactical version for that result. An example of individual and group printouts show, that both printouts are for different reasons. Individual printouts are for detailed analysis and group printouts are for better comparison of all finalists.
All this information must come out during every next day of competition, because then swimmers and coaches have fresh memory from the day before races and analyses of parameters are very effective for the next competitions.
DIFFERENT TACTIC DURING THE RACE
comparison
weighting
You have to look how the world best results were made and compare it with results of Your swimmer. You will find that You made a start or turn even better than the winner, but You were slower in the beginning or in the end of the race. You will find that the same result can be done with different competition analysis parameters. This indicates that each swimmer has his proper individual qualities. If You have better swimming speed and not very good turn speeds, You can make the same result having better turn speeds and worse swimming speed. Sometimes You find that Your start is not the best one, but Your finishing speed is excellent. It is up to You how to plan and construct Your individual tactical plan for the competition today, having the ability to make today's starts, turns and finishing. It is also easy to predict Your result for tomorrow, according parameters of Your start, turn and swimming. You can be sure of Your result if You know what You can do.
For better use of Competition Analysis parameters I made analysis with parameters from the last World and European championships. As a result, 26 different regression models were constructed for all men and women swimming distances. They will help us to understand the main trends of tactics used nowadays in high level swimming performance for each swimming distance. Regression models help us to evaluate individually each high level swimmer's qualities more objectively. It is possible to indicate to weak points of last performance, but what is most important it is possible now to predict and simulate individually how to make better results in the future. All this information is in the computer program with database and very easy to use it.
Technique Charactaristics
Now, if everything is analysed from competition, we need to go deeper, answering questions like "Why is my turn so slow?". For analysing that, to find what is right and what is wrong, we need to construct technique models.
While constructing the swimming technique requirements, it was proceeded that the swimmer should represent the scientifically proved individual variant of movements. In a training process, both, the coaches and the swimmers, should be able to easily apply the movements as required. Proceeding from this, the technique of competitive swimming, starts and turns has been created in the following way:
Technique of starts, turns and strokes is described and studied as a system of movements consisting of phases:
if a phase changes - the aim of movements will change as well;
one phase includes the movements of the whole body;
each phase is determined by the clear moment of the beginning and the end;
all the determined phases appear to be useful on the different variants or individual style;
all moments from one phase into another are considered as the positions of the swimmer, describe the co-ordination.
Methods of construction of the technique consist of the determination of movement parameter variations received from good swimmers. More informative parameters are found, and the correlation of movements and differentiation of the mistakes is determined, taking into consideration the aim of phases.
The technique is determined by presenting assignments for every phase and movement. The general assignments of the swimming technique should be:
avoid unnecessary movements;
achieve the optimum combination of contraction and relaxation of muscles;
guarantee the harmony of breathing action and movements;
produce propulsive forces;
reduce the action of resistance forces;
guarantee the transfer of force from one part of the body to another, with right timing through locked joints;
maintain the dynamic balance of movement.
The optimising of technique is determined according to the mathematical regression analysis, the prognosis of the possible variants of movements for the much better result in the future. Video-recording system was adjusted for the under and above water video-recording of the swimmer, allowing to register the movements of the swimmers at the start, turn or swimming. Video-camera is moving with the adjustable speed parallel to the swimmer. Hardware and software for computer were constructed for measuring of parameters and their analysis.
As a result of the extensive work with national teams of many countries and world best swimmers during the last years, numerous experiences for all variants of swimming styles, as well as for the starts and turns, could be gathered. Such, the probability of the requirements is corresponding with the swimming results. All the 15 technical parts used in competitive swimming have been constructed as models: 4 styles, 4 starts, 4 turns + 3 turns for the individual medley. Special testing system for improvement and control of technical preparation of swimmers was created for practical work and named as "KINEX".
Integrated method of technical preparation of swimmers using the testing system "KINEX".
The usage of wrong technique results from lack or incomplete movement image. According to the very simple approach the IMAGE of MOVEMENTS consists of several parts:
VISUAL IMAGE
ACOUSTICAL IMAGE
KINAESTHETIC IMAGE
VERBAL IMAGE
For teaching it is necessary to create for the swimmer, as complete as possible, the image of movements. It means, that the information for the right swimming technique must be saved into the memory of movements by using all possible ways. The lack of self-control results from incomplete and not integrated image of movements.
Usually the coaches and the swimmers have big problems with the correcting of swimming movements. The repeating of wrong movements has no desired effect, and technique does not change. The only way is to first correct the IMAGE. Our scientific experiments with different sport activities show that by correcting the VISUAL image you can reach up to 80% of skills for the simple movements, but then you still need 20% and the others must assist. Swimming movements are very complicated and for success we need ALL listed parts of the IMAGE to be integrated. It means, that when a coach tries to work with technique in the usual way - showing videos (visual), explaining (verbal), shouting the rhythm during swimming (acoustical), doing exercises on dry land and special technique exercises in water (kinaesthetic) - then success is not good enough, because separate exercises do not create the complete image for movements.
How to integrate?
The main integration unit is VERBAL image. If you are working with the visual part and showing the video-clip, then at the same time you must explain and also the swimmer must think when following your orders. If you are working with the kinaesthetic part and making exercises you must control your proprioceptive feeling by verbal description (was it strong or relaxed, early or late, etc.). The same with the acoustical work, you must think about the verbal or digital descriptions of periods of different rhythms, listening to the sounds during your swimming. Special attention must be paid to the verbal image. All verbal descriptions have to be short, understandable and integrated with some other parts of image. It is necessary that verbal advice for movement is accompanied by some digital number helping to make difference by quality or quantity. Good and bad is not enough, that's why you need seconds for a duration or period, meter per seconds for speeds, centimetres for stroke lengths, and angles for joint fle xion or amplitudes. The swimmers must be introduced to the aims and requirements for each part of the movement. Special attention should be paid to the verbal descriptions of important positions of movements. For correct using of verbal descriptions in practical work, we put it in totally different, untraditional mode:
descriptions of parts - phases
name and main aims of each phase
requirements to movement elements during phase
descriptions of positions between the phases
main digital parameters of movements, phases and positions
Verbal descriptions are more useful and practically effective if we print out the details which need correction. Digital parameters must be followed by evaluation marks as "good" or "bad" and simulated new values.
Now follow the practical advises for the exercises creating kinaesthetic image, integrated with visual and verbal ones.
Imitation exercises on dry land
The purpose of imitation exercises is to create a correct kinaesthetic perception, to acquire the self-control methods. The program of exercises on dry land includes imitation of positions on dry land. The question arises why positions should be imitated. The answer is that changing from one phase into another have the decisive importance. If the initial position of the phase is correct, it means that the arms, legs, the head and the body are in the best position, then throughout the whole phase it is possible to perform the correct movements. If the initial position is wrong already, nothing comes out of the further action either. On the other hand when all the movements have been performed correctly during the previous phase one would naturally reach the correct final position of the phase which is the initial position of the next phase, etc.
Imitating exercises may be performed individually, in pairs or three together. The positions will be taken on the exercise-bench, with the help of three or two swimmers- one holds the arms, the other legs. In order to increase kinaesthetic sensitivity and to form a better image about the movement in memory it is necessary while imitating the positions to perform static efforts in positions in the right direction and for many muscle-groups at the same time. The static effort must be performed in the direction of the right movement but, using the isometric contraction. To verify the integration of the visual image, the imitation exercises of the positions should be performed also with closed eyes. If the correct position is taken with the eyes closed, it means that kinaesthetic perception has been firmly achieved which is the precondition for mastering the further skills.
An important and effective influence in mastering the movements is the description of the positions verbally. When the swimmers listen to the descriptions given by the coach and act accordingly to them, they are not able to memorise them as effectively as the descriptions of their own. The given information "goes in one ear and comes out the other", but what you have explained and described yourself verbally, is memorised better.
The best form of performing such dry land type exercises where imitation includes verbal descriptions of orientation, is where one swimmer assists the other to imitate the position, puts it into words, and describes where the hands and legs are. Then the parts will be changed. This way both can imitate and also describe the right instructions verbally. In the training of the top-level swimmers the imitation of positions is used together with verbal descriptions in the state of light hypnosis which has given good results in improving their deeply rooted mistakes of technique. To sum it up, after imitation of positions on dry land, give effect in the following exercises in water. On the basis of teaching observations we may conclude that the transfer of exercises from dry land into the water is noticeable especially in the co-ordination of swimming movements.
Performance of technical exercises in the water
For better use of the requirements the technical exercises performed in the water should be directed to:
perfecting the movement of a certain phase;
polishing the movement of a certain part of the body, and
developing the co-ordination of movements as a whole.
All the exercises should be performed with high concentration of attention.
The program of technical exercises in the water integrated with requirements consists of the following:
Exercises for perfecting the movements of the arms, legs and the body separately, for example we swim in freestyle by one arm stressing the active start of the pull, after that the same with the stressed high position of elbow, etc.
Exercises for the movements of one part of the body only, swimming in freestyle by one hand stressing the pull, push, speeding up, recovery, etc. at the same stroke.
Exercises by elements for accomplishing the requirements in full co-ordination with concentrated action, for example the exercise 10 x 50 m. Attention should be concentrated on 5 requirements. Every requirement should be followed twice.
Exercises with special equipment increasing speed, increasing push power in start or turn.
In every swimming style, start or turn there are more than 50 requirements for technique, providing enough technical exercises for several periods of training in one year.
Work with video and computer for testing swimmer's technical skills
For the recording of swimmers' movements on tape you can use normal video equipment with special underwater system. It is important, that the main view for swimming movements, starts and turns is from the side view. For start you need 2 video-cameras; one for movements above, another for underwater part. For swimming styles front view, back view, views from the bottom and above the water are useful. To many views are not good for practical testing and analysis; you must select two or three according to your possibilities and needs.
After video-recordings the swimmers must have an analysis and discussion about their technique with the coach.
For measuring some movement's parameters from video you need a computer with a video-board. The video-board represents a system permitting to link the electronic computer display with the video-image screen. Relocating the computer's marker with the mouse along the screen it's possible to measure parameters. In the course of testing the quality of technique is analysed by some details (the catch must be active; the push-off powerful, the arms are together, etc.). Special software has been made up for analysis using the video frame by frame or watching the video-tape forward and backward, slow-motion, replay and still picture of positions. The program has been elaborated so that the swimmer himself may fill up a list of requirements followed on the display. After the last requirement is analysed, the computer will promptly display the mark, given according to how many mistakes occurred in each phase or totally.
In the course of testing quantity of technique, the parameters must be analysed as well. With the special software, the mark is given for each parameter of technique which serves as basis for the computer calculations. If your parameter is nearly to ideal the mark will be "very good", if far from it, will be "very poor". Thus the mark given for any parameter depends on the individual level of the swimmer's results. Then follow so called simulations individually for each swimmer. The key principle lays in the answer to the question "What will happen if you will change something in your technique?". Indeed, before one begins perfecting technique, both the coach and the athlete must secure assurance that perfecting technique will lead to better results. One must know what to alter and to what extent. That's were the computer will be handy: it will offer trustworthy directions and value of alterations, will count possible results for each change. If you input your wish, then the computer will calculate the value of parameters necessary for that. Simulation may be carried out in this way: The coach and the sportsman together discus modification variants of technique and conclude what to alter and to what extent.
Graphic analysis of movements with the computer is used for more detailed visualisation. The computer programs are intended for the interactive analysis of movement. They can be used for many purposes: For editing the original movement. It is possible to change the individual style in the picture. It is possible to place more swimmers' movements on screen at the same time to analyse their difference. In the animation mode, you will see a cyclic movement on the computer screen, which is impossible to visualise by using video. For example, if you have 2 stick figures, then you will see simultaneous movement of both figures on the same screen. Figures can be represented in different ways:
as a silhouette;
set trajectories;
increase speed;
decrease speed.
Very useful is to show path of arm stroke and leg kicks. Everybody knows those curves from the swimming books but now they have a chance to analyse their own. With using this kind of computer animation it is possible to create nearly 100 % visual image for any swimmer.
Conclusion
This kind of approach for technical preparation of swimmers is more professional and it helps to:
find new variants in technique according to individual styles
develop the swimming technique without imitating the movements of the world best swimmers, which has been in use up to now
control the technical preparation
To plan technical work for a year it is enough to test swimmers 2-3 times: at the beginning of the season, during the winter competition period and during the last pre-competition weeks for final corrections before main events in summer.
The effect of the created method has been proved by scientific experiments with the swimmers of swimming clubs and national teams and it gives positive results.
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