SWIMMING SCIENCE BULLETIN

This article is a demonstration of how modern technology supports an ever expanding universe of resources. It describes how Australian athletes are using resources in the United States virtually as if both were in the same city. It remains to be seen how many more applications using modern communications technology develop to enhance the coaching services of organizations in the quest for improved sporting performances.

What is described is an Australian swimming organization taking underwater videos for stroke analysis at a morning training session, sending the videos to the USA for analysis, the analysis being performed, and the results being returned to Australia in time for delivery to the head coach and swimmer at the afternoon training session.

Setting

The athlete (WR) analyzed, from the Carlile Club in Narrabeen, Australia, won gold and silver medals at the 1995 World Short-course Championships. The race-speed stroke depicted in this sequence was filmed during a morning practice at the New South Wales Academy of Sport pool where the Carlile Club trains.

The selected stroke was captured onto a Macintosh 8500 computer and transmitted via the INTERNET to San Diego State University. Using Adobe Photoshop software, the images were trimmed and enhanced as best as possible. Frames were chosen to show important aspects of the stroke sequence. The analysis was formed in MS Word and the pictures placed in the text. The completed analysis and its illustrations were then emailed back to Forbes Carlile, Principal of the Carlile Organization, in time to provide feedback for the swimmer and coach at the afternoon training session. This is now a routine procedure for the Carlile Club's High Performance Training Squad.

Since this analysis is from a lateral perspective, it is assumed that what is exhibited by this viewed side of the body will be mirrored by the other as is required by the rules for swimming this symmetrical stroke.

Frame 1 - Initiation of Arm Movement

Features of this frame are as follows.

1. The longitudinal streamline profile of WR is not flat but rather a double wave with crests at the arm pits and the top of the thighs. Theoretically, it would be most desirable for this line to be straight but it is possible that a perfect alignment could never be achieved because of the requirement to perform considerable vertical movement components in the breathing and kicking actions of the stroke.
2. The hands have just started the outward pull which is directed slightly upward. By moving upward, the body and shoulders will remain down in the water hopefully until it is necessary to initiate a vertical action, possibly to breathe.
3. It would also be hoped that the upward action would cause the feet to rise from the low trail position that they occupy here.
4. One might criticize the position of the feet as not being streamlined. However, When the amount of vertical movement in breaststroke is considered, upon return into the water after breathing it would not be possible to attain a perfectly flat position. The feet and hands would be below the line of the trunk and shoulders. If these downward movements at the extremities were not performed then the whole system would sink, causing excessive wave resistance and probable increased frictional resistance.
5. A possible improvement might be to have the face profile looking directly at the bottom. The smoothness of the crown of the head might be a better leading edge for the frontal profile of the swimmer than the more irregular facial topography. Also, the slight lowering of the head that would result might contribute to a higher and more streamlined chest and/or legs/feet position. With that minor modification it might also be expected that the hips would lower very slightly so that the lower profile of the whole swimmer would be flatter as opposed to the current wave-like line. On the other hand, the face position could indicate an earlier-than-desirable head lift as part of a slow and deliberate breathing movement.

Frame 2: Mid-Outward Pull

Features of this frame are as follows.

1. If an observer was not to know that this was a breaststroke sequence, the position displayed in this frame is almost that of a classic butterfly stroke.
2. The arm position is at mid-outward pull and force is being generated slightly backward by the high bent-elbow position. The hands are still "high" (near the surface) and so forces created are likely to pull the swimmer directly forward.
3. The position of the head is of concern. The suspicion raised in Frame 1, that the face profile was not a static position but rather, the initiation of a slow and deliberate head rise to breathe, is confirmed. The angle of the face profile, neck, and chest is anything but streamlined. It appears to create a larger than necessary frontal profile that would cause considerable resistance and loss of streamline. Hyperextension in the thoracic spinal region is starting to occur.
4. Since the head action is slow and vertical, the chest drops slightly as a reaction since the hips and feet have remained high and the head is still under water. This unnecessary oscillation of the trunk would create detrimental wave resistance. Although the longitudinal flow line of the lower profile is smooth, its waviness will create resistances that are unnecessary. They ultimately will detract from forward progress.
5. The first obvious feature of improvement in this stroke has to do with the breathing action. The head lift has to be delayed at least until the inward pull is in progress. That would require the vertical movement of breathing to be achieved in the shortest time possible. This would result in the disruption to streamline occurring for a shorter period and maximum streamline being held longer. That this slow head movement causes the chest to drop is cause for real concern. If the movement is delayed until the inward pull is in progress then the vertical movement might be offset by force from the pull and no reaction in the chest would occur.
6. It is because of the reasons outlined above, that it is good breaststroke form to initiate the head movement for breathing on the inward pull, completing it as quickly as possible, and returning the head to a flat-face profile with deliberate vigor while the hands drive forward.

Frame 3: Initiation of the Directional Sweep

Features of this frame are as follows.

1. The longitudinal profile has improved as the chest is higher as a result of the head breaking the surface. The feet and hips remain high in a desirable position. However, the frontal profile, demonstrated by the line along the chest, neck, and face, is exaggerated and would cause unnecessary frontal resistance. Hyperextension in the thoracic region continues to increase.
2. The problems generated by the early head lift are compounded further at this stage of the stroke. The positions of the elbows and forearm clearly show that force in the arm movement is being created mainly downward to lift the head and shoulders. The forces created by the hand-forearm at this stage are more vertical than horizontal.

   Theoretically, at this stage of the stroke the forces created by the pull should be propulsive rather than supporting vertical movements. This is because when the arms are wide the moments of force are greatest and have the potential to fatigue the swimmer if they are excessive and unproductive. One could assert such is the case with WR. At the position where the hands should be sweeping smoothly in an accelerated fashion, but pitched to create forward propulsion, they are instead supporting an unnecessary energy-sapping non-propulsive movement. Too much of the forces created by the total arm pull will be lost through supporting the slow-breathing action. This means that the efficiency of the pull and the potential of WR to swim fast will be decreased.

3. If the head was still down, the arm pull most likely would be modified to be less bent at this stage because it would not be necessary to create forces so large. Smaller forces on faster, wider moving hands would generate as much power but in a propulsively dominant manner as opposed to the limited propulsion possible in the exhibited position. This wider outward pull would set the stage for the inward pull to be more propulsive and forceful because it would be initiated from further out and at a higher speed.

Frame 4: Mid-inward Pull

Features of this frame are as follows.

1. The feet and hips still remain high and streamlined.
2. The head and shoulders have continued to rise slowly, in relative terms to ideal theory, and must have been supported by the inward pulling action (since no body parts other than the arms have created proactive forces).
3. The path of the hands continues to go down during this stage of the pull. That has to occur to support the slow deliberate movement of the large mass of the shoulders and head. It must be appreciated that slow movements usually consume more energy than do quick movements and one has to ponder how much of this energy loss contributes to difficulties in events where endurance is a large factor (e.g., 200 m races). Slow head and shoulder movements also will cause an exaggeration of the depth of the pull.
4. The angle of the hand/forearm once again indicates the main direction of forces. One would estimate that the major portion of forces created here are vertical rather than horizontal. The inward rotation and pitch of the hand would support this interpretation. It is worthwhile to comment that to swim the type of stroke demonstrated here would require great strength and may be an explanation why WR gets slower, relative to his world rankings, as the distance increases from 50 to 100 through to 200 m.
5. The dynamics of this stage of the stroke are far from desirable. This part of the pull should be more horizontal than vertical despite needing to balance a head lift. The head and shoulder action employed compromises the whole arm-pull effectiveness.

Frame 5: End of Inward Pull

Features of this frame are as follows.

1. The propulsive potential of the inward arm pull has ended. The knees are starting to bend as preparation for leg recovery. The head and shoulders are still out of the water
2. The position of the hands is particularly low, being almost at the same level as the knees. This is caused by the slow and defective breathing movement. It has been necessary for them to stay low to support the large mass out of the water.
3. The streamline profile of the torso and legs is near its worst for the stroke. This is a necessary evil but it could have been improved by the hands being higher, that is, instead of being well below the elbows, they should have been in front of or higher than them.
4. At this stage, all actions should contribute to achieving maximum streamline as quickly as possible.

Frame 6: Initiation of Recovery

Features of this frame are as follows.

1. The hand/forearms have swept in and up to a much greater degree than elbow movement. This would contribute a vertical force component in the stroke. Although some vertical movement is required the action exhibited here exaggerates that necessity.
2. A telling feature of WR's profile is the angle of the neck. It is still vertical and this is the third frame in the stroke where the large mass of the head is held out of the water. The time that the head is out of the water and the profiles of body parts are out of streamline has to be minimized at every opportunity. It is fair to say that WR's whole stroke is distorted and compromised because of the breathing action.
3. This frame exhibits the position of least streamline with the hips and knees at their deepest. Such a position has to be attained but the more that it can be minimized the better. Ponderous movements that have been suggested from this analysis will exaggerate depth.

Frame 7: Kick-ready Position

Features of this frame are as follows.

1. The legs have been drawn up into a fully compressed position and are just starting to kick back.
2. Between this and the previous frame, the hips have risen markedly and the arms thrust vigorously forward, being slightly over the surface at this time. This places the lower edge of the trunk through to the hands in a position that is approaching a flat and streamlined alignment. This means that at the highest propulsive phase of the kick it will propel a streamlined upper body as opposed to one that might be falling down into the water if the streamline-attainment action was slower. This is a good feature. The kick will now be able to thrust the swimmer forward as opposed to have to develop some reaction force to a falling body.

Frame 8: Maximum Kick Propulsion

Features of this frame are as follows.

1. Indeed, the torso, shoulders, head, and arms are approaching a flat position. What is interesting to note is that the position cannot be perfectly flat. Because of the structure of the knee joint the kick has to travel downward to a certain degree. Also, the lowering head, shoulders, and arms also create a vertical force-component. It is necessary to create counteracting forces to stop this verticality. The kick alone cannot balance the force of the mass of the upper body, head and arms. Thus, the position has to be slightly curved to create a capture surface (a "scoop") to slow the downward movement of the upper portion of WR's physique.
2. Often in breaststroke, a question is asked "How should the hands be held on the stretch forward?" The answer is clear in this frame. They have to be flat to create the largest "stopping" surface possible to decelerate the large portion of the body which is being driven forward and down.
3. WR completes the action to a position of streamline similar to that exhibited in Frame 1.

Conclusions

It is not easy to prognosticate what will eventuate in a complex human movement such as a swimming stroke if a movement segment is altered. It is obvious that the slow head and shoulder actions have to be changed. The features of the "new" action that should be incorporated are as follows:

1. Hold the face profile horizontal until the sweep-round after the outward pull is completed.
2. Lift the head and shoulders as quickly as possible attempting to avoid hyperextension of the thoracic spinal region.
3. The height of the head lift should be as low as possible. It is likely that the face profile will never exceed 60 degrees.
4. Have the head lead the speed of all these actions as well as using it to minimize the magnitude of movements.
5. The breathing, torso-lift movements have to be accomplished within the time of the inward scull and the initiation of the kick backward. This is a very short period and will require meticulous attention to adherence and execution.

Once these features are implemented, a reanalysis should be performed to see how and whether or not all other factors in this dynamic stroke have changed.

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