The butterfly swimming , also butterfly or dolphin , is a swimming technique. It was recognized by the World Swimming Federation in 1953 as the fourth official swimming type . The FINA looked at this step forced to a clear differentiation from the traditional breaststroke make.
In the 1930s, David Armbruster, a trainer at the University of Iowa , developed butterfly swimming from the breaststroke technique. By bringing their arms forward over the water, innovative breaststroke swimmers reduced their water resistance. Because of the increased effort, these swimmers usually only swam a few meters or a lane in the butterfly technique and then switched to the usual breaststroke technique. It was only through further refinement of the technique that butterfly swimming became more economical.
When pulling the arm, both arms are simultaneously guided under water from the front to the back with a slightly S-shaped pulling movement, the so-called keyhole pull, and then brought straight back over the head. Breathing forward is usually every two puffs. The legs were originally moved in a straddle strike, which later developed into a whole-body wave movement ( undulation ), which continues from the chest to the feet. Two leg kicks are performed per arm stroke. The second is stronger than the first.
The butterfly swim is considered to be the second fastest type of swim after the crawl swim and the second most strenuous after the properly performed breaststroke. In competitions it is completed at distances of 50 m, 100 m and 200 m.
With the introduction of the closed leg kick , this type of swimming was called the dolphin technique for decades , while the butterfly technique continued to be understood as the use of the sternum kick . The sternum stroke has not complied with the rules for several years. Due to international names, the swimming position is now called butterfly worldwide and is therefore officially called butterfly in German .
The FINA rules stipulate that from the beginning of the first arm stroke after the start and after each turn, the body must be kept in the chest position and both shoulders must be in line with the surface of the water. Leg kicks to the side under water are permitted. Movement of the legs in the horizontal plane (sternum swing) is not permitted. After the start and after each turn , a swimmer is allowed to do several leg kicks and one arm pull under water, which must bring him to the surface of the water. The swimmer is allowed to go up to 15 m completely submerged after the start and after each turn. At this point the head must have broken through the surface of the water. The swimmer must stay on the surface of the water until the next tack or finish.
Both arms must be moved backwards and forwards at the same time under and over water. All movements of the feet and legs must be done at the same time; Simultaneous upward and downward movements of the feet and legs in a vertical direction are allowed. The feet and legs do not need to be on the same level, but reciprocal movements (crawl kick) are not allowed. A sternum swing movement is no longer permitted, except in explicitly designated Masters competitions for swimmers with a minimum age of 20 years. At each turn and at the finish the float in both hands must simultaneously strike .
- Competition regulations swimming (PDF; 422 kB) of the German Swimming Association (DSV) as amended on February 12, 2018