<p>Flipper for swimming or underwater activities or muscular training, comprising a blade (1) and a shoe (2), the ends of which facing one another are dynamically and kinematically separate. The blade (1) has extensions (8) projecting backwards and fixed to the shoe (2) in areas substantially corresponding to its central part, and provided between the blade (1) and the front part of the shoe (2) are elastic tie-rods (11) designed to control angular variations between the blade (1) and the shoe (2).</p>
