Even the dolphin, like the frog, represents an artistic swim, which is however usually taught as a third style precisely because it is the biomechanical succession of the support - grip - pull - push gesture, typical of the crawl and the back.
Data sheet
Type of movement
Simultaneous, symmetrical and cyclic for both the upper and lower limbs.
Body position
Prone: the simultaneous movements of the limbs and frontal breathing determine a continuous variation in the attitude of the body. There is an alternation of inclined positions during breathing and / or on the final thrust of the arms, and more hydrodynamic positions, immediately after the "entry of the arms into the water. A reduction in respiratory acts promotes better buoyancy.
Upper limb movement
There is a distinction between an "aerial action and an" underwater action. The simultaneous movement of the arms determines very effective propulsive phases and aerial actions characterized by decelerations.
The air action is carried out with the limbs extended to avoid excessive lifting of the shoulders and to avoid forcing the shoulder joint too much. The simultaneity of the movements avoids lateral displacements of the pelvis and legs.
The underwater action is distinguished in the support / grip, traction and thrust phases.
The lack of shoulder roll results in a substantial difference in performance compared to the crawl.
The trajectories described by the hands are more external (when compared with the freestyle) and never overlap the midline.
Breathing
It is frontal and is carried out with an extension of the head, which begins to rise when the arms are ending the pull and start the push. At the end of the underwater action, the swimmer inhales, and then plunges his face into the forward action of the arms.
Lower limb movement
a) From a mechanical point of view the movement is similar to the crawl
b) The action from top to bottom causes the pelvis to rise
c) The carrying over to the surface determines the sinking of the flanks.
Upper and lower limbs coordination
Two leg strokes are usually done per stroke cycle.
The first kick of the legs develops on the entrance of the upper limbs
The second is during the pushing phase of the arms and, if you breathe, coinciding with the lifting of the head
This last movement of the legs has a propulsive function and at the same time stabilizes the body which is found to be rather inclined due to the lifting of the head and the sinking of the hips.
Some swimmers perform only a leg kick, the one during the entry of the arms in the water.
BIBLIOGRAPHY
Lorenzo Boscariol - Notes on theory, technique and teaching of individual sports: swimming.
Lorenzo Boscariol - My experiences as an instructor
Aldo Guerra - Theory, technique, didactics of swimming sciences - Year of edition: 2000 - Calzetti e Mariucci editori.
James and Brian Counsilman - The New Science of Swimming - Zanichelli.
Other articles on "Swimming Dolphin"
- Swimming breaststroke
- Exercises and swimming training
