This section of the report contains many detailed tables and graphs. To simplify the presentation I have taken the license to "translate" what is contained in the sections. The reader is encouraged to obtain a copy of the report and study the biomechanics section. Concrete reasons for one athlete swimming faster than another are directly revealed in the swimming and non-swimming skills of a race.

Race Strategy Analysis

In the 200 m butterfly, Melvin Stewart had neither the longest stroke nor the highest turnover. His propulsion speed was a result of an optimized combination of the two and was almost the same as that of Michael Gross. The placing difference between the two swimmers was attributed to Stewart's superior start, turns, and finish.

In the 100 m breaststroke for men, Norbert Rosza had a particularly fast start and the highest stroke turnover. His distance per stroke was the least. His success was the result of a high level of fitness that allowed him to maintain the stroke rate. Technically, he is not as good as other swimmers but for a 100 m "scramble" he can override those deficiencies. That explanation is verified by his 200 m performance. For that event he lengthened his stroke and decreased the rate. His start was also slower. One has to question why would he opt for a start that was .23 sec slower than the one used in the 100 m. There should be no difference in start speed for any event since it is a closed skill. His turn and finish skills also were deficient in the 200 m. For this athlete, attention to the non-swimming skills could significantly improve his 200 m performance to the level of being very close to Mike Barrowman.

In the women's 200 m backstroke, Krisztina Egerszegi displayed an individualized combination of stroke length and rate, neither of which was the best in the race, but which resulted in the fastest velocity. Anna Simcic missed the bronze medal by .03 sec. She had the slowest turns. If that non-swimming skill was improved she would have been well into the medal placings.

Implications. It would appear that attention to the details of the non-swimming skills of starting, turning, and finishing would make big differences in achievements at the highest levels of swimming. At these world championships, gold medals and world records were often determined by the efficiency of non-swimming skill execution particularly when two or more swimmers produced very close to the same velocities. The importance of maximizing these skills as part of normal training cannot be overemphasized. Another significant feature was that neither stroke length nor stroke rate alone produced the best swimming speed. The subtle combination of the two modified by the individual needs of the swimmer produced the optimum swimming velocity.

Butterfly Analysis

The strokes of Anthony Nesty and Hrvoje Baric were compared. Arm actions were the primary focus of analysis.

  1. The path of Nesty's pull is relatively direct for both hands. There is a slight outsweep and insweep. However, the finish action (primarily the change to elbow extension) is almost directly backward. The path is not an "S" shape. The change to extension is not smooth as force dropped markedly resulting in a two-peak force curve and a brief drop in swimming speed. On the other hand, Baric's pull was more of a classic S, the finish action being outward rather than directly to the rear. His force curve had a single peak.
  2. Both swimmers displayed a long application of force suggesting that the length of effective pull (insweep plus finish) is the period that produces increased forces and acceleration.
  3. Despite butterfly being a symmetrical stroke, neither swimmer had matched arm strokes or force curves. Sharp direction changes or corrections reduced effective propulsion. [This suggests an appropriate teaching strategy would be to have swimmers concentrate on a constant feeling of pressure on the hands until the arms leave the water.] Both swimmers corrected their asymmetry in an individual manner.
  4. The kick produces propulsion. This is a feature that needs to be trained. Unfortunately, the type of "butterfly" kicking that is done on a board has little similarity to that done in the stroke. [It would seem that the best training for this stroke's kicking would be to accentuate it in ultra-short interval training. The power of the kick should match the power of the entry and finish to avoid an imbalance occurring.]
  5. Nesty's entry was wider than Baric's. This allowed him to apply force backward earlier in the stroke. Baric's narrow entry required an exaggerated adjustment in the outsweep. That incorrect placement and the adjustment contributed to an increase in resistance. [Narrow entries require an extended period for repositioning which contributes to deceleration.]
  6. Baric's hands also slid into the water while going forward. This produced an added resistive force that slows propulsion. In contrast, Nesty's left arm extended over the water before entering which minimized any resistance and produced an underwater pull that became effective very quickly.
  7. Nesty's COFG velocity was more constant than that of Baric. It resulted from an economical and smooth application of force. There was little in his stroke that produced any jerk or obvious increase in effort. A smooth phased stroke is more economical in terms of energy expenditure.

Summary. The major features of the butterfly stroke technique are:

Backstroke Analysis

The strokes of Krisztina Egerszegi and Jeff Rouse were analyzed. Particular attention was paid to their arm actions.

  1. Rouse's velocity curve fluctuated less than Egerszegi's because his pull pattern sustained an effective force application longer. Egerszegi's was disrupted by an uneven, but effective, kick.
  2. Rouse displayed an action at the end of the stroke which portends the future. Instead of pushing back and down, his finish is almost directly backward. When his arm extends he then turns his hand towards the body and does an inward and upward sculling action that maintains force application in much the same as is done in some synchronized swimming stunts. This results in the thumb leaving the water first at the start of the recovery. In contrast, Egerszegi's right hand changes direction abruptly at the end of the backward action resulting in increased resistance and a marked deceleration. [Rouse's form of hand action and extraction is very different to the outmoded "little-finger-first" action that is still commonly taught.]
  3. Both swimmers have a temporary drop in force application when their hand changes from the upsweep to the downsweep/finish. [Smoothness of the transition from the two phases should be a major teaching emphasis.]
  4. Egerszegi's stroke is more typical of backstrokers;
  5. Rouse's action was more efficient than Egerszegi's;
  6. Rouse displayed a consistent kick while Egerszegi's was inconsistent. This contributed to Rouse's consistent force development. On the other hand, Egerszegi's inconsistent kick was largely due to having to produce two large kicks to counter a weak right-hand entry.

Summary. The major features of the backstroke are;

Breaststroke Analysis

The strokes of Mike Barrowman and Linley Frame were compared. The general theme of the analysis was that Barrowman's technique is the current model for emulation.

  1. Barrowman's greatest asset is his streamlining. Not only does he carry his body flatter than other swimmers, he also minimizes the time that his body is in a non-streamlined position (e.g., during breathing and leg and arm recoveries).
  2. Barrowman is in the lunge forward stage when he inhales as opposed to Frame's being vertical. The lunge limits resistance while the vertical position increases it (Frame almost stops during this action). This means that there should be no slowing or stopping of the hands to accommodate breathing during the inward scull or recovery.
  3. Barrowman's hips stay low even when the shoulders are raised to facilitate breathing. That stability limits the amount of vertical movement in the stroke, a further aspect of efficient streamlining.
  4. The peak height of Barrowman's hips occurs during the extension-glide phase of the stroke. At the end of each stroke he assumes a maximally streamlined position with the hands, head, shoulders, hips, and legs all in the one plane. This timing of the hips contributes to an undulating wave that travels down the body and adds to propulsion because the wave is faster than the swimmer's velocity.
  5. In contrast to Barrowman, Linley Frame's hips are highest during the recovery, just after her peak shoulder height. This means that the swimmer's whole system goes up and down as well as incorporating a body wave. That verticality increases resistance. [The teaching point is do not encourage excessive hip and shoulder movement. Only instruct to produce a wave-like action. Any exaggeration of the shoulders and hip movements will slow rather than accelerate the swimmer.]
  6. Barrowman's outward scull moves up as well as out producing a circular action. It is likely that there will be a gradual change to the inward scull because of that circularity. That should allow force to be maintained rather than being lost as usually happens when abrupt changes in movement direction occur. In contrast, Frame's outward scull is flatter and even produces a negative effective force component, possibly because of a poor angle of attack of the hands. Her hands produce little effective force in the early part of the outward scull while Barrowman's is already propelling. [On the outward scull encourage the hands to go out and up to produce a circular hand path in the lateral plane. While this is being accomplished the swimmer should be low in the water behind the forces that are being created. There should be no attempt to swim over the water or on top of the pull.]
  7. Barrowman's very fast and early leg recovery keeps his mass moving forward as well as accommodating a fast and consistent hand recovery. On the other hand, Linley Frame's slower and later leg recovery is either the cause of or caused by the pause at inhalation. [The simple implication is that swimmers should consciously minimize the time they are not streamlined in the stroke. Barrowman's timing, fluency, diminution of recovery time, and streamlining during the kick are very effective.]
  8. The angle of attack of Barrowman's hands allows no backward slipping. By sculling effectively outward and inward he is able to move his body past an established hand position. Frame lets her hands slide forward several inches, thus, slowing the forward progression of the body.
  9. During the latter part of the inward scull, Barrowman has his hands pressing slightly backward, an action that facilitates propulsion and body lift to initiate an over the water recovery. [This contrasts to the usual fault in the inward scull where its effectiveness is limited because of recovering the hands too early or changing the angle of attack of the hands to facilitate slipping into the recovery. It is interesting to note that Norbert Rosza also has this slight rearward thrust at the end of the inward scull.]

Summary. The major features of the breaststroke are:

Crawl Stroke Analysis

The stroke patterns of Summer Sanders, Catherine Plewinski, and Joerg Hoffman were analyzed. Several generalizations were drawn from the examinations.

  1. The pulls were relatively narrow. There certainly is no exaggerated "S" shaped pull. In one swimmer the hand that showed the greater force production was the hand that minimized lateral movement. The directness of pull could be caused by an increased shoulder roll. [It would seem that "S" shaped pulls are incorrect, thus, disputing the touted Bernoulli theorem explanation for forward propulsion. Anchoring the hand and moving the body past a fixed point appears to be a better description for developing propulsion. Forces are greatest when the hand presses backward and minimizes lateral slip.]
  2. If the hand slides into the water as part of the entry, and continues forward under the water, it increases drag. Although, the other arm may be pulling while this occurs and progression continues, effective force is decreased by the amount of resistance created. [The best arm recovery is one which stretches over the water and enters in an extended position. That allows forces to only be created in a vertical or backward direction.]
  3. The only propulsive forces are created in the insweep and finish phases of the stroke, the stage when the hand can apply force in a horizontal plane. [Since the entry/outsweep action produces little propulsion, the time spent in that phase should be minimized but not to the extent of unnecessarily increasing resistance or disrupting smoothness of action.]
  4. Most swimmers have asymmetrical underwater pull patterns. Part of the difference is caused by the breathing action. [It is likely that bilateral breathing will do much to minimize differences.]
  5. There is very little difference in the pull patterns of sprint and distance swimmers, the mechanics being very similar.
  6. Sprinters maintain their velocity more effectively than distance swimmers because of consistently strong kicking. [It would be erroneous to attempt to strong-kick in distance races. The extra fatigue incurred is a greater liability than the benefits to be gained.]

Summary. The major features of the crawl stroke analysis are:

Return to Table of Contents for ICAR 1990-91 Report.