@Cleopatra Sorina Iliescu for sure.. the A-frame is what I learned waaaay back and we've evolved away from it for many reasons, including that it requires you to overextend in the air (rather than reach full extension in the water), it wastes a lot of energy, prevents you from using your max power, and, as you note, it puts you at risk for injury. Also, as far as I'm aware, there is only the A-frame that's formally known as a "frame." The D frame you mentioned in your original comment is actually the D stroke, rather than a frame (sorry for not catching that!), and requires slicing into the water from the side rather than a catch from directly above the water (which is my preference).