Even the dolphin, like the frog, represents an artistic swim, which is usually taught as a third style precisely because it is the biomechanical succession of the support gesture - grip - traction - thrust, typical of the crawl and the back.
Data sheet
Type of movement
Simultaneous, symmetrical and cyclical for both upper and lower limbs.
Body position
Prona: the simultaneous movements of the limbs and the 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 of more hydrodynamic positions, immediately after the entry of the arms into the water. A reduction in breaths favors a better attitude.
Upper limbs movement
There is an aerial action and an underwater action. The simultaneous movement of the arms determines very effective propulsive phases and air actions characterized by decelerations.
The aerial action is carried out with limbs extended to avoid an excessive raising of the shoulders and to avoid forcing too much the scapulo-humeral articulation. The simultaneity of the movements avoids lateral movements of the pelvis and legs.
The underwater action is distinguished in the phases of support / grip, traction and thrust.
The lack of shoulder roll causes a substantial difference in performance compared to the crawl.
The trajectories described by the hands are more external (if compared with the free style) and never overlap the midline.
Breathing
It is frontal and is carried out with an extension of the head, which begins to lift up when the arms are ending the traction and begin the push. At the end of the underwater action, the swimmer breathes in, and then immerse his face in the arm's forward action.
Lower limbs movement
a) From a mechanical point of view the movement is similar to the crawl
b) The action from the top downwards causes the pelvis to be raised
c) The surface transfer determines the sinking of the sides.
Coordination of upper limbs and lower limbs
Usually two strokes of legs are performed per stroke.
The first stroke of the legs develops on the entrance of the upper limbs
The second during the pushing phase of the arms and, if you breathe, coinciding with the lifting of the head
This last leg movement has a propulsive function and at the same time stabilizes the body which is found to be rather inclined due to the raising of the head and the sinking of the hips.
Some swimmers perform only one leg stroke, one during the entry of the arms into the water.
Edited by: Lorenzo Boscariol
