Popular Science Monthly/Volume 23/May 1883/Position and Stroke in Swimming
|POSITION AND STROKE IN SWIMMING.|
PERHAPS there has been no science—at least none of equal importance—that has been less developed theoretically than swimming. The essay of Franklin upon the subject, although an answer to the inquiry of "how to swim," is merely an article with advice as to when and how long to bathe, and the narration of anecdotes of his experience in swimming. In the literature of the subject we fail to find any practical directions that could assist a novice in learning to swim; for this reason we propose briefly to analyze one or two important points, which, if put into practice, will make it an easy matter to acquire the art.
It has been the writer's experience, in teaching beginners, that the great difficulty lies, not in the inability on the part of the scholars to master the correct stroke, but in the fact that while using the correct stroke, for a certain reason, they find it difficult to keep their heads above water Some of the scholars did not lack in determination or bravery, and yet their efforts were fruitless. They would apply the correct stroke with great force, and yet eventually their heads would sink. Finally, the complaint of one of the scholars, to the effect that the effort seemed to tire the neck more than any other part of the body, led to a contemplation of the cause of the fact.
While investigating the facts in the case, it was observed that a beginner throws himself upon the water in a stiff and straight position, not allowing the body or back to bend at all, but merely bending the neck. He kicks his legs in a vertical direction, tending to raise the back to the surface of the water, and thus places himself in a position parallel to the line of the surface. It is easily seen that he must bend his neck nearly perpendicular to this line of direction in order to keep his head above water (see Fig. 1). We have merely to try this
position on land, to experience its difficulty and disagreeableness. The muscles of the throat are greatly strained, while the air-tube is nearly closed, causing difficult respiration.
It is not to be wondered at that the learner soon relaxes this unnatural position of the head, and gives up the effort to keep his face above water. But, when the correct position is once mastered, this difficulty disappears, and swimming is made as natural and easy a function of the body as running or walking.
Fig. 2, showing the correct position of the body while swimming, has been drawn from empirical analysis, and is as plausible in theory as in practice. All of the propulsory exertions should be given so as to have but one tendency—that of advancing the body directly forward. (The proper method for accomplishing this end will be spoken of further on.) Now, admitting that the whole tendency of the stroke is to force the body in the direction of the component, c, if the body be so bent that the chest and part of the abdomen will form a resistance, making an angle with the direction of the force—as a, b, c—the tendency of that resistance will be to form a resultant in the direction
of b, which forms, with the natural buoyancy of the body, the force that keeps the head above water.
A concomitant advantage in the position under discussion is, that the neck and head are free to take their natural positions, and hence the avoidance of the evil referred to in speaking of the position of the head assumed by beginners.
The greatest difficulty to the beginner is to learn to keep the proper position of the body after attaining it. This difficulty can only be overcome by using the proper stroke after having placed the body in the correct position.
In the use of the arms, the only direction that can be given is to remember that, when the arms are thrust forward at the beginning of the stroke, such position of the elbows and hands should be taken as will make the least resistance to the water. To accomplish this, the hands should be placed palm to palm, and the elbows made to come quite close together, starting them from under the chest, as in the cut. In making the effective part of the stroke, our object is to get a forward motion only. The arms and hands should be so placed as to produce the greatest resistance upon the water. To accomplish this, the palms of the hands should be thrown outward, and the plane of the direction of the stroke of the arms made parallel to the surface of the water.
The most important and the most often defective point in swimming is the mode of using the legs. It would be well for a beginner to observe the swimming of a frog, for undoubtedly the same method of using the legs should be adopted by man as is displayed in the model swimming of that amphibian.
In analyzing the stroke of the frog, we notice that there is no vertical motion; the whole direction of the force is in a plane exactly horizontal, and is accomplished by virtually opening and closing the space between the knees—offering the sole of the foot as a resistance while kicking, and placing the feet in a position of least resistance while recovering.
In accomplishing the first of these conditions—the opening and closing of the space between the knees—the knees should be thrown out, and the contraction of the legs made slowly, in order to cause as little resistance as possible to the headway already attained.
It will be found that, if we alternate the stroke of the arms and legs by giving propulsion with one while recovering with the other, a more constant buoyancy will be attained, and, for long swims, it will be found far less fatiguing.