rajankäyntiä

Räpyläkäynti, sometimes referred to as finning in English, is a swimming technique primarily used by marine mammals, particularly seals and sea lions, to propel themselves through water. It involves the rhythmic movement of their hind flippers, which act as powerful paddles. The flippers are typically held together and moved in a sculling or whipping motion, generating thrust.

Unlike the alternating leg kicks used by humans for propulsion, the flipper movement in räpyläkäynti is more coordinated and often involves a degree of undulation of the body as well. This allows for efficient forward motion and maneuverability. The shape and size of the flippers, along with the musculature of the hindquarters, are key adaptations for this mode of locomotion.

This swimming style is highly effective for navigating aquatic environments, allowing these animals to achieve considerable speeds and pursue prey. The flexibility of the hind flippers also enables precise steering and quick changes in direction, crucial for hunting and evading predators. While primarily associated with pinnipeds, some other marine animals may exhibit similar propulsive movements with their hind limbs, though the term räpyläkäynti is most specifically applied to the characteristic motion of seals and sea lions.