shinfin fins are used as Multiple Sclerosis fins because they teach a horizontal body position and good streamlined kick. The trick is to relax and let the fins flow naturally.
shinfin fins have a “natural resonance”, so you can just let the fins guide you without thinking about it. This works for people with MS, swimming on their front and back. It can be almost instantaneous and very dramatic. Also, the fin “natural resonance” kick pattern tends to hold for a while even after they take the shinfin fins off. People remember the feel of the kick.
If you have difficulty controlling leg movements, the natural flexibility and flex of shinfin fins will guide you to a more streamlined kick for freestyle, backstroke and fly. The fins are specifically designed to encourage a streamlined kick. They guide your muscles to achieve a natural rhythmic movement. Their ability to help overcome difficulties with movement control is very impressive.